My sister lost her baby at 8 months

My sister just recently lost her baby at 8 months. Second time. First time was at 4 months and this time at 8 months. I just can't believe this. My oldest sister has one kid. I have one baby girl who is 5 months and my only sister who was left trying to have one can't have any. I feel so devastated for her but she doenst really talk to me and if I text her or call her to show her my condolences she'll probably get mad at my other sister or mom for telling me. I don't know what to do. I keep thinking about it and imagine if I would have lost my baby, I would have lost myself completely.