Big amen, Nancy. Big amen.
To aunty though. It is actually a GOOD thing that she is at least interested in reading about borderline. If she had no interest or denied it, there is no chance she would change. It is NOT easy and requires very, very intensive therapy and working very hard. I hope she does the hard work it takes to learn how to control her back and f orth emotions. Dialectal Behavioral Therapy is awesome for borderline!
Having said that, you still can't fix her. She has to fix herself. But I do appreciate the love in your heart. I am very angry at your brother.