Since she was diagnosed, what sort of professionals has she seen? In my opinion, a counsellor and a dietician aren't enough, she should be seeing a psychologist and more importantly, a psychiatrist. Depression and eating disorders go hand in hand and the depression exhacerbates the eating problems. Did she begin puberty early? The reason I ask is that girls who begin puberty earlier than their peers are more likely to develop eating disorders. Also, if she did, that could indicate part of the problem is chemical. A psychologist might want to try Cognitive Behavioural Therapy.