So sorry for your troubles.
I would get her and yourself to Alateen and Alanon. I know she doesn't want to go, but with my kids, when they didn't want to do something (join a team or something) I told them they had to go 5 times and if they didn't want to go anymore, then at least they would know what they were saying "no" to. They ALWAYS stayed for the duration, but didn't feel "committed" if they didn't like it.
I think if she attended some meetings, she would REALLY benefit. She would learn that she has choices and doesn't have to accept calls from her mum, if she so chooses. She would learn she didn't cause it, she can't control it and she can't cure it. And, she will meet other kids that are dealing with the same thing, which is such a gift for her at this point.