(((Chrysalis123)))
I'm the adult child of an alcoholic. I know how painful this can be. My best advice is to let her feel all her feelings and work it out. My dad used to pull things like this all the time. His favorite was "disowning" us when he was mad. He did this right before my high school graduation, then called to ask what I wanted as a gift like nothing had happened. My mom said to just tell him how I felt, so I did. It was liberating to say the least.
She will have scars over these things, no doubt, but being in therapy will help more than you know. Does she have a journal? Maybe you can get her one so she can continually get this out and work through it. Also, anger letters can help. I would suggest asking her therapist about this because she's so young.
As for you, hang in there! It took some time for my sisters and I to realize it, but the best thing my mother did for all of us was divorce my father. Lord knows what kind of shape we would be in if she hadn't.