Tension in family over pregnancy (long, sorry)

enuk2013

I'm hoping someone on here can give me some advice on how to handle a delicate situation in my family:

My SIL told me in July she was struggling with infertility. She was very supportive and excited when I told her (in an effort to be sensitive) I was also trying to get pregnant. When I asked how to handle if I got pregnant first, she said to just behave normally, that she'd be happy for us. Nevertheless, sharing that I was pregnant when it happened was really hard because she visibly struggled to be happy. She did say the right things and sent a nice "congrats" card too. That was October and we haven't seen her since (not at all over the holidays or family gatherings). They live 10 minutes away and we were close prior to this. My brother (and only sibling) told me a couple of weeks ago that she simply can't be around me right now, it's too difficult for her. (For his part, he feels torn between his excitement over being an uncle and being sensitive to her feelings.)

I was fortunate to get pregnant relatively quickly and have no close friends that have dealt with fertility issues. My heart goes out to her because I know this must be brutal for her, but I simply do not know what to say or do. My husband is getting pretty offended at this point, and since my family is small and close, it creates tension with my parents as well who also feel torn between being excited and being sensitive to her feelings. She is a wonderful person that I love dearly and we've never had any issues before.

Anyone have any advice for me?