(((((Dawn))))),
I am struggling with similar issues with my husband although he is not physically ill. As you probably know, meds are not very useful for BPD. Is she getting any kind of psychotherapy? That would be my recommendation, maybe even some family sessions. I don't really know how to cope with this situation myself, you know. I'm just trying to get my husband back into therapy.
I've also heard that we need to read the book Walking on Eggshells. It's about how to deal with people with BPD. I'm glad you reminded me of this. Sorry I'm not more help. I just wanted to say I totally empathize with you. And I will add you and your mom and dad to my prayers!
Love and hugs,
Eddie