My sister in-law is 36 and has a speech impediment. My fiancé says she doesn’t function like an average 36 year old and has a disability but when asked the name he had never been able to tell me. She lives on her own, worked at a book store, drives and flew to England to spend time with her boyfriend. There are times when she gets giddy about boys or wants to be married but doesn’t seem to understand finances and everything it takes to raise a a family. She receives SSI.

Anyways she calls me and will disclose how her mom calls her fat, tells her to lose weight, not have black hair or nail polish. I’ve witnessed the mom tell her to stop eating or dismiss her while she treats her son like the golden child. She took a photo of her in a swimsuit and showed it to her saying look at her back fat. At the grandmothers funeral the mom introduced my fiancé and me to people and the stepfather had to introduce her and say and this is our daughter!

She recently told me that her moms friend who had been visiting tested for covid but my fiancé and his mom never told me. Our daughter visits weekly so I felt that should have been disclosed. I asked my fiancé and he told his mom his sister told me about the friend.

His sister texted me asking why I opened my mouth and she’s getting bitched at and her parents hate her now and never talk to her again.

I feel like talking to the mom but she doesn’t do well with confrontation. For some time now I’ve come to truly dislike how she treats her daughter and wanted to say something. Her daughter has called me crying and saying she tried to cut herself.

I just don’t know how to handle this situation!