I think the friend and her mother's actions are understandable and were the right thing to do. The information should never have left the faculty office, though. That teacher, and any other staff involved, owe Asa a major apology.
I don't blame Asa for being angry at her friend, though. She's been through a lot and you can't expect her to think things through clearly. Hopefully, with time, they're able to patch things up. From the little we've seen, her friend seems like a decent person.