Sister with BPD is hurting our brother
I'm the eldest, my sister is 3 years younger than me and diagnosed with BPD, medicated but not in therapy currently, and we have a younger brother who recently got married and just had a baby.
Now that me and brother both have kids my sister took it very badly. She refuses to talk to any of us and acting out badly. I think it's hard for her to show joy when she's deep in her existential crisis about babies and kids and families.
We are all survivors of a very bad childhood, our abusive dad died just a few months ago, we are finally orphans, we only have each other, because there's not much family left.
My brother invited us to a party to celebrate the birth if his first son, but she refuses to come (which is reasonable) and refuses to tell him she's not coming and why (which is a bit offensive). I told her I think she should at least talk to him about it, but acknowledging something she is doing may not be 100% amazing automatically counts as critisism, and now im completely blocked too.
On the one hand she keep acting out and waiting for me to judge her, she uses it to fuel her own issues with herself, on the other hand, when I refuse to criticise her, she's acting out even more. This time I said grey things like "you should talk to your brother" and she found a way to milk it as a judgement even though its not.
Im tired of these games, of walking on eggshells and never having just a normal conversation with her, of her needing reassurance like a kid, but twisting it in a hurtful way somehow.
My brother just needs a family right now, he shouldnt have to deal with a grown woman throwing him away for her issues while he's in the newborn trenches. She'll hurt him badly and im not sure what to do.
I feel exhausted and hurt and confused on how to handle this.