My long distant girlfriend suffers from Bulimia, how can I help?

Ok this is a bit complicated, my girlfriend is bulimic and I really want to help her and I can see that she wants to help herself as she has seeked the help of a therapist, but her mother isn't supporting her and she just tells her too eat and dont throw up which isnt helping her at all, I have another problem, my girfriend lives 900km away, so I barely get to take her on dates etc, our relationship is mainly consisted of skype calls and facebook chats so it is hard to do things like take her on dates to places that arent surrounded by food. DO you have any advice on ways I could help her other than just supporting her and listening to her and being there for her, because Im doing all that and more and it doesn't seem to be changing much. I call her beautiful every day, but I dont know if that helps because I am drawing attention to her appearance. She gets bouts of severe depression and I always sit and listen when this happens but I dont know what else to do to help. Thank you for reading all this.