My future sister in law and my fiancé have a very rocky relationship. It stems back to an issue many years ago where she found herself in a really awful situation and her family, including my fiance who was in his early teens at the time, essentially abandoned her. The entire experience was clearly very traumatic for her — she literally brings it up every time I see her — and I truly feel for her that she had to go through this.
I've talked with my fiancé about it and he agrees that he wishes he could go back and change the situation. He's taken a few steps in trying to restore his sister's trust in him, but the efforts are only half-hearted. What I'm trying to say here is that he could try harder, but at the same time she never directly communicates what she needs or wants from him either. Basically, they're both to blame.
Not surprisingly, she's in a dysfunctional relationship. I think she projects a lot of their problems on to me and my fiancé. I think she resents our relationship and searches for its cracks. She's a part of my bridal party, but every time I see her she just goes off on rants about how she hates her brother, how I'm too good for him, and how I really need to figure out what I'm getting myself into etc. We've been dating for six years and living together for three, but when I hear her talk about him it's like she's talking about a different person. It's like she zeroes in on his flaws, exaggerates them, and blinds herself toward the good in him.
This situation is just completely stressing me out. My fiancé is flawed, but he is kind and caring toward me and gives me what I need out of a relationship. My family and friends all love him, and I've never been happier or a better person than the years we've been together. I hate the idea of someone who doesn't support our marriage playing such a major role in our wedding day. Really, the whole family needs to go into therapy together to deal with the older issue, but they're not really the type to deal openly with their emotions, so I think that's a highly unlikely situation. Any ideas for how I can make this situation manageable, if not for his family then at least for me?