Last year my SIL stayed with us for a few days. To put it mildly, it wasn't a great visit and I was glad to when she went home. During her stay, she fell out with DH and one evening started screaming at him, calling him every name going. This followed on from a drunken jibe that she felt her brother had changed and was clearly sexually frustrated. She made this remark to myself. I ignored her at the time but since this visit I feel like she's tried to exclude me from things.
She's going through a divorce. When it first happened, DH told me and said not to say anything as she hadn't wanted me to know. This shortly followed on from me receiving a birthday card that I didn't find amusing and felt she was mocking me for being unattractive with the card and content. She has since reactivated her FB account and has added every other family member, excluding myself. I am not going to beg and send a friend request, but I honestly can't think what I have done. We also have a family WHatsAPP group. When I post a photo on there of DS she sees it, but never replies (replies to everybody else), but when DH posts a photo of DS she's all over it.
I know I am probably be sensitive, but she really irks me and it leaves me feeling like an outsider. Family gatherings are always a bit awkward too. DH thinks I've offended her - if anything, its the other way around, but not sure if I am just being silly and unreasonable!?!