I watched this twice and consistently tried to find the place where we found out that she had an eating disorder. I couldn't find it, until I finally realized she did not have an eating disorder. She felt the need to stop eating because her dead twin told her that she needed to feed him, and that is why she stopped eating. She did not have an eating disorder prior to him dying. He told her that he needed the nutrients to stay alive, she was eating perfectly fine before that.
