im so sorry to hear that she is struggling. I wouldn't try to force anything on her, whether it be food or a talk.. thats what my dad tried and pushed me further backwards.
instead i'd just let her know... if she feels like shes falling backwards, if she feels up to it to talk about it, immediately do so. Some times i can be talked through a relapse.. but when im on my own, there is no stopping me. im headed for destruction.