Advice for dealing with difficult family (long)

PedsMom

Hello to the board, I'm new to the bump. I am almost 11 weeks right now. I would appreciate advice on dealing with a (not typical) issue regarding family reactions to pregnancy. My husband and I are anomalies in our families- we both come from difficult childhoods (to varying degrees) but have managed to be relatively functional in our relationships and successful in our respective careers. Although we have relationships with our parents and siblings, in some cases we have had to set significant boundaries to maintain healthy relationships (mainly for my family- my husband's family is not quite as troubled). Most of them have reacted positively when we recently told them that we are expecting, but my sister has been a notable exception.

To give some background, this was not entirely surprising. She has struggled with substance abuse for the past several years (currently in a methadone treatment program) and has also had a lot of financial and relationship problems. We were close growing up- she is my only sister and we were often each other's only support system in unstable home environments- but she has become increasingly volatile over the past 4-5 years and pushes people away, while lamenting that nobody is "there for her" enough. She reacted to news of our engagement and wedding with a very negative attitude- questioning our relationship, making negative comments about marriage in general. She agreed to come to the wedding but had to be practically begged to participate in things like the family dinner the night before, she was one of the first guests to leave, and I doubt she cracked a smile the whole time- every picture I have with her in it from that day she looks either angry or near tears. She seems to feel resentful of me for not ending up with the same problems even though we come from the same background, and upset that I have "not been there" for her (I moved out of state for part of my graduate education for several years and recently moved back near her, but she seems upset that I moved at all, although I continued to call her regularly and flew her out twice to see me as well as visiting her every time my busy schedule allowed).

So I did not expect her to greet news of my pregnancy with smiles and hugs, but she seemed to at least take it without crying or yelling and we left on good terms (I thought). That was almost 4 weeks ago...she has not returned calls since and responds only sporadically to texts, usually with brief statements like she is busy or tired. She has told our mother that she is angry at me over an argument we had months ago (when I wouldn't loan her money), but we had discussed that and moved on from it awhile ago so it is strange that she would decide she is angry about it again. I think this is about the pregnancy, but she knows she doesn't have a rational reason to be upset about it so she is latching on to whatever reasons she can come up with to be mad at me.

I'm kind of at the end of my rope with her- it's one thing to be a crappy sister to me as an adult, but I don't want my kid growing up with an emotionally unstable aunt who can't respond to positive events with normal human emotions. At the same time she is my only sibling, I feel bad that she has the problems she does in life (and understand where it comes from, having grown up in the same households, even if we did take different paths), and if at all possible I would love for her to have a positive role in her niece or nephew's life. I don't know what to do or say to her to address our problems, especially as she isn't returning my calls. We are having thanksgiving at our house this year and she has said she is coming, although I don't really want to get into things then. I would appreciate thoughts or advice, particularly if any of you have had similar situations during a pregnancy and can share how you dealt with them.