MIL and life help

My MIL has been living with us for almost 4 years. She moved in to help watch our kids while we worked. Things started out okay but pretty quickly it got uncomfortable. We are very different people and I think it bothers her. Over the years her treatment of my has gotten worse and it has been really bubbling up for the last year.

After her other son announced that him and his wife were expecting, she really has had one foot out the door.

This weekend we butted heads. There was a lot of her family in town and my husband asked her to give us a heads up if people were coming over. On one of the mornings she messaged that she is on her way with someone. I was a bit pissed. I have two young kids, one who isn’t feeling well and we slept like garbage and now I have less then 10 min to make my house semi presentable.

When she arrived I asked if in the future she could give us more of a heads up. She got pissed and said this was her house too. I asked her to think about it from my perspective, how would she feel if when she was in the trenches of raising young babies if her MIL brought family over unannounced. She really didn’t care and kept saying think about it from my perspective.

Over the 4 years living together I have only asked her to do things differently 3 times. And every time she gets really mad when I set a boundary. My therapist says she displays narcissistic personality disorder traits. (For context, she used to listen into my therapy appointments) . Anyways, I am at my wits end. I want her gone but a big part of me feels really bad doing that to my kids. They love their grandma and she does really well with them for the most part. is it selfish to choose my sanity over consistency for my kids?

I feel like if she doesn’t leave I need to. My husband is 100% on board for asking her to leave, he is at his wits end too. But again I struggle with the impact this will have on my kiddos.