It is possible that she has wry neck which is a neurological symptom that includes twisted neck, walking backwards, or turning in circles. It can be a symptom with a head injury, a vitamin deficiency, Mareks disease, and in other severe infectious diseases. Many use vitamin E and selenium orally to treat it. A poultry vitamin containing vitamin E, added to the water plus some chopped egg, tuna, or nuts daily can add selenium to her diet. Poultry Nutri-drench or Poultry Cell vitamins contain both E and selenium, and dosage is 1 ml per 3 pounds of weight daily by mouth. Hopefully she won't continue all her life to have this problem. We really can use your expertise her on BYC since you are in vet school. The importance of this forum is that many don't have access to a vet who treats poultry. My daughter is a vet, and said that she got pretty minimal teaching about chickens while attending vet school. Nowadays, since more people have backyard flocks, there could be more money to be made caring for poultry.
Here are a couple of links to read about wry neck: