This is why I went no contact with my mother. I have a trans son and an agender child; she continually misgendered them both and didn't even try to check herself. My in-laws are not, uhh, progressive, but they've always respected my kids. Guess where we still celebrate holidays?
I have a lot of feelings about this but the most basic is that starting in 2016 I think a lot of people were put in the agonizing position of choosing between their kids' health and safety and having a relationship with their parents, and that's no choice at all.