Would it be easier to write letters? They are a novelty nowadays so it might seem even more special. Plus, you could prepare yourself ahead of time for reading her responses and know there isn’t pressure to immediately reply.
I have a sister with bipolar. She’s a teacher and type a personality. When she’s in crisis, I just listen.
I don’t know what advice to give because if anyone says something she doesn’t like, she flies off the handle and starts screaming. So I just listen.
If I can I try to reassure her she’ll most likely be ok like for instance if it’s a health scare I’ll tell her the odds of her having that condition and not to worry until the drs tell her to worry. But mostly I just listen. Then I deal with my own emotions and thoughts after.
Sorry I don’t have any great advice. I know it’s tough. Hang in there.
My sister has, errr, problems of her own, let’s say. I listen, like @LilyoftheValley. I don’t give her advice even if she asks for it because she doesn’t want advice, not really. She just needs to know someone is there. Maybe your sibling is the same?
My twin brother has schizophrenia and when we get together it really triggers me. I haven’t seen him in a few years but I talk to him on the phone sometimes.