A little bit of a back story: About six years ago, one of my cousins committed suicide (he was 22). After that, his mother/my aunt kinda lost her mind and would send my mother horrible messages via calls, texts, social media, etc. She would call my mother names that are so awful I can't repeat them, wish my sister and I dead...all kinds of horrible things. They live in different states, so she hasn't done anything physical but I wouldn't put it past her if she were closer. Though we've blocked her from every platform we can think of, the messages have continued sporadically even as recently as last month. And we're not the only family members this has happened with - she has basically isolated herself from her siblings (my mom and her are cousins, but were the closest thing each other had to sisters growing up). It's a really sad situation, and I feel awful for my mom for having to deal with this. If my sister or I see one of the messages before she does, we delete it and don't even tell her.
Needless to say, my aunt is NOT invited to my wedding. I want to invite my cousin (the sister of the one who died), but I'm not sure how to ask her for her address and also ask her to be discreet about it from her parents. She's aware of the situation and certainly not part of it, but I can't exactly be like "hey your mom's nuts...don't tell her you're invited but she's not..."
Any advice on how to handle this? I'm at a total loss. Should I just not invite my cousin? Other members from that side of the family are invited so I would feel bad excluding her...please help!