I got engaged in February, and picked out my bridesmaids soon there after. I have six total: 2 of my college friends, 2 friends from work, and my 2 sisters. (one is older, one is younger) Now, since I'm not particularly close to my sisters and since they live half a state away, I asked my best friend to be my MOH. My sisters didn't care, because it meant less work for them.
In July, my sisters had a falling out. No one is quite sure why, but it has lead to some tension since my older sister pretty much wanted the rest of the family to cut my little sister out. No one is willing to do that because the fight seems petty (honestly, neither of them will way what happened, so we have no reason to just stop talking to her). My older sister then picks a fight with me over politics, tells me I have no career (I'm a chemist in a forensics lab, but whatever), that I don't know the "real world" because I live close to my parents and not the "big city", and that she knows more about my field than I do (she went to school for art). Since then, we have not spoken. I reached out to her on multiple occasions since then to say hi, or to talk wedding stuff. She has never answered, and instead whines to my mom about how I have it easy, and I feel like I'm entitled (neither of which are true -- I worked full time and when to school full time for both my degrees). I wished her a happy birthday last month, and got no answer. She also blocked my fiance on facebook for no apparent reason. She's been very angry with my parents through email and phone calls over random things; she also has a history of dependency, both on prescription drugs and alcohol. She's heavily in debt. My mother thinks she's jealous over me getting attention over the wedding while she herself isn't getting married (which isn't our fault -- she's dating her boss and no one can know).
I'm beginning to freak out a little bit. I need to get bridesmaids dresses done NOW. The wedding is in June. The easiest route would be to just say, screw it she's not in the bridal party anymore, but I can't: my mother is paying for the ENTIRE wedding and wants my sister to be in it.
I don't know what to do. Even if she does 1)get a dress and 2)show up (and those are pretty big ifs), I am terrified of her behavior at the wedding. I'm at a complete loss and beginning to freak out.