What you're doing is very kind. I woukd think it's okay. But be careful to protect yourself. In a way, what happened gave you valuable information . . . to let you know how psychologically damaged this lady is by her congenital disorder. It sounds like you're not personalizing her bad behavior toward you, which is mature of you.

Are their other people who are responsible for her welfare? It might be appropriate for you to compare notes with them, as to the extent of how badly she decompensates. This is apt to happen again.