I'm sorry that things are not improving. How old is she? We have never discussed the possibility of this being Mareks disease. Wry neck and then lameness are signs of it, and since the vitamins haven't helped, it could be possibly be Mareks. I don't know how you will handle this if she doesn't get better, but if she dies, I would get a necropsy done by your state vet to look for Mareks. Please let us know how she gets along and I really think that you have given your all for your chicken to make her better. Sometimes it just isn't possible.