How To Deal With A Toxic Sister-In-Law

Ah! The pain of settling into married life was not enough that now you have to deal with a toxic sister-in-law. That woman was supposed to be your friend, but things turned the other way around. Well, you are not alone. 

My friend Rita, says “My sister-in-law tends to control each decision that my husband or other family members make. It feels like she’s running the whole family even when she doesn’t live in that house. She’s manipulative, and always meddling in personal boundaries. I’m tired of this behavior. How do you deal with a toxic sister-in-law?”  

I can understand that handling families can be tricky, especially after marriage. But it gets challenging when there’s a constant source of stress – your toxic sister-in-law. 

Don’t worry! Many women have dealt with toxic families (including yours truly), and I’ll help you setting boundaries with toxic sister-in-law respectfully. To understand the family dynamics with a sister-in-law who is rude, controlling and constantly gets on your nerve, we looped in Shruti Doss, Clinical Psychologist and the founder of The Mynd Space to share her expert advice. When we asked her why does this sister-in-law situation arises, she explained, “From a therapeutic lens, conflict with a sister-in-law often isn’t about the sister-in-law alone. It taps into family hierarchy, belonging, and power shifts after marriage. When you enter a family system, roles get rearranged – and not everyone adjusts healthily. A toxic sister-in-law may experience your presence as a threat to her position, closeness, or influence, even if she isn’t consciously aware of it.”

So first takeaway is – its not about you, it is about her insecurities, lack of understanding and a pivoted sense of worth. Let’s head on to find answers for you.

How Do You Know Your Sister-in-Law is Toxic?

Your sister-in-law demands the same things that you have. She treats you as a competitor. She is married and settled in her own home but tries to control your family. It’s more like your in-laws’ family functions as she says. Does that all sound familiar? 

If yes, these are some signs of a toxic sister-in-law, and you’re dealing with a challenging relationship. This is a very delicate relationship, where she is the daughter of the house, your husband’s sister, and you are labelled as the ‘outsider’. Ouch!

Yes, it hurts and you are at the centre of it all. But, before we dive into solutions, let’s first identify some more signs of a toxic sister-in-law. It’s important to recognize the toxic behavior to understand how to deal with it. 

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1. She constantly criticizes you

It’s like she’s always looking for something wrong with you or what you do. No matter your effort, it’s never good enough for her. She’ll find something to complain about. As trivial as ‘you didn’t do the dishes right’. ‘You don’t keep the house tidy.’ 

Or, when going to a family gathering, she spoils your mood by saying you picked the wrong clothes to wear. The color does not go well with your skin. Yes, she could get personal, more often than you’d realize.

A friend of mine shared her incident, “Once I had planned a date night with my husband and decided to cook his favorite meal, but I’m not that great at cooking. And, my sister-in-law drops by uninvited that day. My husband and his sister are too close, so he didn’t complain and asked her to join us for dinner. As soon as we started eating food, she reacted with faces. I know I’m not very good at cooking, but what I did was for my husband.”

So, does your sister-in-law do such things? Always criticizing you, even about the tiniest things and disguising the same as her “genuine feedback“? There is no doubt you have a toxic sister-in-law as family, much to your dismay. Shruti adds, “Constant criticism is not feedback – it’s a form of emotional dominance. We often see that chronic fault-finding is used to: Lower your confidence, Reassert superiority, Keep you emotionally unsure of your place

Over time, this can lead to self-doubt, hypervigilance, and people-pleasing – especially in women who already feel like “outsiders” in the family.”

Yes, it can be really annoying and your self-confidence can touch rock bottom. It might get hard to relax or enjoy things when she’s around. Since her ultimate goal is to make you feel like you can’t do anything and she knows everything, here mere presence could trigger you and spoil your mood.

Remember, it’s her fault and not yours. 

2. She’s a drama queen

The whole family revolves around your entitled sister-in-law (or much like what she wants). Like she’s in a constant need for attention and when she doesn’t get it, you know what can happen! One minute everything’s okay, and the next, boom! There’s a whole new problem. 

It’s like your narcissist sister-in-law is the star of a never-ending soap opera, and you’re just amongst the extras. She gets involved in an argument very quickly and can turn a simple conversation with you into a dramatic scene. It’s exhausting trying to keep up with her emotional roller coaster. Shruti explains the issue and also shares an expert solution, “Drama is not accidental. For some people, chaos keeps them central. When everything revolves around their moods, reactions, or crises, others stop questioning them – and start accommodating them. This is why setting boundaries with dramatic people often increases drama before it decreases.”

While it may appear almost impossible to set boundaries with her, considering she does not respect any, it is still the best thing to do. It will be rewarding for you once you stand your ground.

3. She’s two-faced 

Why do her actions and words do not match? Because she lives in some imaginary castle where her subjects have to deal with her two-faced personality. What it is, you ask? Let me loop in Shruti here. She says, “Two-faced behavior creates emotional instability and instability breeds control. When you never know which version of her you’ll get, you unconsciously:

• Walk on eggshells
• Overthink your words
• Doubt your own reality

This is relational unpredictability, and it’s deeply exhausting.”

Much like, she may get into a huge fight with her difficult in-laws over something as small as going out. She’d call you crying one minute, ranting and gossiping about the incident then next be acting out like she never said all those things.  And, you are left wondering what a two-faced sister-in-law I have. You’ll never know what’s real anymore! 

Plus it’s not just about her in-laws. She may be gossiping about you behind your back – no big deal for her. You just don’t believe what she says. And NEVER confide in her.

She may appear sweet and concerned , and you may just pour your heart in front of her. And then, one fine day you will know how she’s using your vulnerability against you. Classic!

Moreover, here’s how you can confirm that she’s definitely double-faced.

• She’s overly sweet with you one moment and rude the next
• She’s speak ill about others to you (including family members)
• She says something and do something else 
• She tries to be in the good books of everyone (even when she back-bitches about them)

Use your powers (women actually can sense things, even people on Quora have experienced it.) 

So, notice these signs, and if you feel something is not right, don’t talk your heart out to her. Especially, nothing about you and your husband. She may use it against you.

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3. She’s JEALOUS

Shruti said, “Jealousy in sisters-in-law often stems from attachment insecurity, not personal dislike. When a sibling struggles with emotional differentiation, marriage can feel like abandonment rather than expansion. So instead of adjusting internally, they externalize their discomfort – onto you. This is why reassurance alone rarely fixes jealousy-driven behavior.”

Your jealous sister-in-law can’t stand that her parents are loving you the same way they do her. If your father-in-law gets you cupcakes, she wants that too (at the same time, the same flavor, from the same bakery.) So she acts weird. 

In extreme cases, sisters-in-law are likely to be jealous of your relationship with your partner.

Or, they just don’t like seeing you happy and doing well. As per scientific research, jealousy can make people act as rivals! That is why it seems like she is always competing with your- for material things, for affection and even for space. If you are wondering, ‘why my sister-in-law ignores me?’, it is largely because she hasn’t accepted you as family and thinks of you as a competitor only.

Forr example, my best friend’s sister-in-law was super jealous of them. One of them shared that whenever she’d go out with her husband for dinners or vacations, the sis would act like a total downer. She’d make plans that would interfere with their time together. She’d even try to convince her brother that his wife didn’t really care about him. The toxic sister-in-law’s scheming mind totally messed up my friend’s marriage.

4. She disrespects you 

Being from the family, she assumes she is superior to you. It’s like she doesn’t care about your emotions at all. She doesn’t care about your feelings and tries to make you feel small and unimportant.

Imagine you tell her in confidence that you’re upset about something that happened with your mother-in-law (thinking that she’ll help), but she just laughs it off or changes the subject. She may even add her own version and download the same to your MIL. Or, she’d keep telling you how to do certain things in front of your kids. More like making fun of you. 

Another way of disrespecting you is when she does things you don’t like, even though you’ve told her to stop. (Think!)

Maybe you don’t like it when she borrows your makeup, clothes, or even jewelry without asking. If she keeps doing it no matter how many times you say “Please don’t,” that’s disrespectful too. What causes her to disregard you as an equal in the family? “Disrespect often appears when someone does not recognize you as an equal adult.
In therapy, we see this especially in families where: Hierarchies are rigid, Age or birth order equals authority, Marriage doesn’t automatically grant autonomy. Repeated disrespect slowly erodes emotional safety – which is why ignoring it long-term isn’t healthy.”

So, if you can recognize these behaviors, you’re likely pissed and finding answers to how do you deal with a toxic sister-in-law. Let’s find out in the section below. 

How Do You Deal With A Toxic Sister-In-Law?

Toxic sisters-in-law come with various behavioral traits– jealous, controlling competitive and superiority, to name a few. So, once you have identified which one yours is, here’s what you can do. 

1. Don’t let her get to you

Sometimes, the sister-in-law thinks she knows your partner better than you do (according to her, she knows her brother so well.) She might say things like, “Your husband doesn’t like that color.” “My brother likes his chicken rare.”

But, she might forget that you’re now her brother’s wife. So, instead of getting upset, just laugh it off. Show her that you’re confident in your relationship by saying something like, “Actually, I know what my husband likes!” 

This can help put her in her place, especially if she’s younger than you.

2. Kill her with kindness

If your sister-in-law is always criticizing you or your family, it can be really frustrating. The best way to handle this is to stay calm and kind. Be the bigger person and deflect negativity by smiling at her. Start behaving like her comments don’t bother you. 

And, maybe, sometimes, shower her with compliments. That will make her focus on herself rather than you. By not reacting, you’re showing her that her opinions don’t affect you. Hopefully, she’ll get the hint and stop.

And Shruti agrees, “Kindness works not because it changes her, but because it removes emotional fuel. However, as a therapist I caution: kindness without boundaries becomes self-abandonment. The goal is neutral warmth, not over-giving.”

3. Remind her about the basic boundaries

It’s important to have basic boundaries with everyone, including family. Setting boundaries with in-laws and other extended family members should be on your priority list after the marriage.

So your sister-in-law drops by uninvited? Or, worse, she barges into your room without knocking? It’s like your personal life doesn’t matter at all. Ugh! Just talk to her. Tell her that she can’t do it every time. Explain that while you appreciate her wanting to visit, it’s important to respect everyone’s time and space. 

It’s okay to say ‘no’ sometimes and to let her know what is and isn’t acceptable behavior.

Shruti further explains, “Boundaries are not about controlling her behavior. They are about protecting your nervous system, your marriage, and your sense of self. A healthy boundary sounds like:

• “This doesn’t work for me.”
• “I’m not comfortable discussing this.”
• “We’ll decide that together.”

No justification. No over-explaining.”

3 Tips To Set Boundaries With A Toxic Sister In Law

It can be a long long process. You may have to answer a lot of your in-laws’ questions. But, first what you got to do is to take your spouse in confidence. 

Tell him how emotionally draining it is for you to deal with toxic people. He may get reluctant to believe you, I mean, it’s his sister(s) after all. But, you will have to make him understand that he’s married now and you’re his priority. And, all you want is to maintain peace. Shruti explains why this assumes prime importance for your marital bond- “When a partner struggles to see their sibling’s toxicity, it’s often due to normalization. What feels abusive to you may feel “normal” to them – because they grew up inside it. Your partner can seek therapy to unlearn this in order to support you.”

So, here are some tips that you can consider.

1. Have clear conversations 

When she overtakes in your and your husband’s lives, stand up for yourself and have clear boundaries. When she’s being too bossy or too rude to you, immediately point out such things.

By setting boundaries, don’t think of cutting ties with a toxic sister-in-law. It may jeopardize your family relationships. It’s a private matter, so try for a direct approach and have a conversation with her in a calm manner. 

Tell her how her actions make you feel. Let’s say your sister-in-law offer advice on handling your children, tell them “I appreciate it, but I can handle parenting my own kids. Your advice makes me feel overwhelmed.” 

Be clear and specific about what you want to change. If they care about you (even a bit), they’ll try to change for the good. 

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2. Limit your contact with her

Try to keep your distance. If she invites you somewhere, it’s okay to say no. And, when you talk to her, keep it short and sweet. No need to get into deep conversations. Again, don’t overshare with her. 

Let me tell you a story about a friend who had a similar problem. Her sister-in-law was always starting arguments and gossiping about everyone. My friend decided to just smile and nod, and then change the subject. It wasn’t easy, but it stopped her from getting dragged into the drama.

Girl, if she’s the stormy sea, you be the dry land. That’s the mantra!

3. Seek support 

Yeah, having a difficult sister-in-law can feel really tough. And, in this journey of dealing with her, you might feel stressed and upset. You may even feel lonely when you think that ‘my sister-in-law is controlling my husband’, and you can’t talk to him about everything. And then, some of us have husbands who think they do nothing wrong, so how can their judgment not be correct?

But remember, you’re not alone. When you feel that your husband will not understand, try seeking support from your mom. She’ll help you navigate this. Moms know everything!

And, simultaneously, make your husband understand, so you both figure out how to handle the situation.

In between all these, taking care of your mental health is super important. Do what makes you happy – reading a book, going for a walk, or spending time with your pets. 

Or, you can start Yoga. Taking a regular course can help you feel calmer and more confident, backed by studies.

Make your own way to get out of these situations. Reach out to people who care about you, and focus on taking care of yourself.

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Let’s face it – dealing with marriage, a new family, and maybe a new culture can be a task itself. You don’t need another one to tolerate your toxic sister-in-law. You don’t have to let someone make you unhappy. Y

our mental health and well-being are important. Now that you have answers to how do you deal with a toxic sister-in-law, start to act. Set boundaries and stay calm, this might ultimately improve your relationship with your sister-in-law or at least make it more bearable.