TL;DR : my SIL is wanting to help plan my wedding. My wedding is already planned and I just don’t like her. I’m worried that it’s going to blow up into a huge fight and don’t know how to avoid that

My sister in law met my brother about five years ago and has caused drama ever since. She is very self centered and is always blowing up over tiny things and then will forbid my family from seeing my brother and my nephew. I tried to be her friend at first, but two christmases ago I mentioned that I was taking a death of a friend pretty hard and she responded by lecturing me about my friend deserving to die for being transgender. I left in tears and she never apologized but I’m so afraid of confrontation with her that I let it be swept under the rug.

I got engaged five months ago and am getting married in four months. I have seen her multiple times since getting engaged and tried to show her and my brother my ring, but she brushed it off and acted like I was a little kid playing grown up.

I sent save the dates out last week and then we saw each other at a family dinner. When she got there, she immediately grabbed my hand and gushed about my ring, then wanted to show me all this stuff she had found for us to do to get ready for the wedding. I am halfway through my engagement so my wedding is basically already planned. I did tell her that she isn’t a bridesmaid and that they already have their dresses when she tried to tell me what she’s going to wear as a bridesmaid (yeah - yikes), but I could barely get a word in to tell her that I just don’t want to do any planning with her.

At dinner I also kept trying to talk to my family about a huge promotion I recently got and she kept dragging me back to wedding planning. It was just so frustrating and showed me that she doesn’t care what I want and she doesn’t see me as “me”. It feels like I’m just a prop in her story.

I did ask if her toddler can be my ring bearer but she ignored the question in order to talk about her. She wants to plan all of these showers and DIY things (like centerpieces/placemats) but this is all stuff that either my bridesmaids are already doing or that I don’t want at all. She also kept going on about getting our hair and nails done and matching outfits for my bachelorette party and tried to say what we’ll do/where we’ll go for that too. I again told her it’s already been planned as well, but it’s like it goes in one ear and out the other, and honestly the bachelorette party is going to be rough if she’s there. I also do not want to get my hair/nails done or matching outfits and if she paid attention to me at all she would know that I’m a tomboy and I’m not into all that extra stuff.

She wants me to come over and “wedding plan” and I just don’t know what to do or say. I’m honestly so tired of everything wedding related and throwing her into the mix is just adding extra stress. I’m afraid to say it to her face because she screams a lot and then I cry and agree to whatever so I’m thinking about sending a text saying that I don’t want to do any of this, but that might have an even bigger fallout. How can I get her to butt out of the wedding without losing my brother and my nephew? I’ve rolled over for her for five years in order to keep the peace and I can’t do it anymore, but I’m sick with fear over the fallout and I don’t want to lose my brother again.