I think I wrote a similar post a couple of years ago when I was pregnant the first time, but it seems to be rearing its head again now that I'm pregnant again (and feeling super emotional).
My partner's sister has had issues ever since I can remember - at least the entire 11 years I've been with my partner. She got mad when we first moved in together because she felt he was abandoning her. Then again when we went overseas a few years later. When we bought a house, she had a meltdown because their mum invested with us and she didn't think she'd get the same treatment (she would).
When I was pregnant the first time, she'd just broken up with a boyfriend and basically became suicidal. So a lot of my early first pregnancy was spent worrying about her.
Their brother died last year, which made her even worse. She'd met a new guy but they were on and off - and she was a complete mess when they were off.
She went overseas and then came back early, showing up out of the blue on our doorstep with the guy (back on). She randomly comes over unannounced to complain about how bad her life is (she has a job, a ton of money, a great family and a guy that wants to be with her) but never answers my partner's texts or calls when he enquires after her (even though she often texts when it suits her).
She wanted to commemerate their brother's death by coming over for dinner - which was fine. But she ended up leaving before dinner. She then reorganised for the next day, but then texted at the last minute to say she and her guy wanted to stay for a few days because they were about to move into a new place and the existing place was moldy (?). So I texted her and said that's totally fine, but it would be appreciated if she filled us in a bit more often. Because until that point, she'd been going on about how she had no idea what to do with her life and just wanted to 'disappear'. But she was actually looking for somewhere to live with her boyfriend, going to Uni and being offered a new job - stuff that someone who wants to 'disappear' doesn't do. She then didn't show up when she was supposed to, and when I asked why she texted to say my partner knows why and it's all too hard. It turns out my comment about asking her to be more forthcoming was so upsetting she couldn't possibly face me.
Their brother's death affected me greatly as well. I knew him for 10 years and was a mess for a lot of last year. But she treats me like an outsider, never talks to me properly, but feels like she can come to our house whenever she wants.
My partner understands my frustration but is worried if he says anything to her, it will push her over the brink. I just feel so helpless because while I feel she is disrespectful and manipulative, I also worry about her mental health. She refuses to see a counseller, and both her parents are worried about her, but they all tiptoe around the issue. It's doing my head in and I don't want to be stressed out while pregnant. It does also affect my partner's and my relationship at times because he gets defensive on her behalf, even though he does agree with me - but he feels trapped in the middle. It's not even that I'm upset for me half the time - I'm upset how she treats him because I can see how worried he is. I just don't know what to do. There have been so many other moments like this where she's texted my partner about wanting to kill herself (in a roundabout way) and then not getting in touch for several days - and it's turned out she went away with her guy for a holiday or something (that did actually happen).
Any advice? Even just a virtual hug?