I would cull her. I had a severley cross beaked easter egger that looked very much like yours. We watched her suffer trying to get enough to eat. She finally was eating all day and not able to keep full. We culled her. She was so skinny. I was devastated that I had let a chicken suffer so long. (I think she was about 10 weeks old) She was skin and bones. I will never, ever do that again. I still feel guilty about it.