This is wry neck, stargazing, crook neck, and many other names, but it is a symptom of vitamin deficiency, head injury, or disease. Start her on poultry vitamins in her water that contain B1 thiamine, Vitamin E, and selenium would be good to add to the mix or food--25 mcg daily. PolyVisol without iron infant vitamins may also be used with selenium--give 3 drops daily by mouth. In some cases, prednisone may be used. Here are some links for you:
http://www.browneggblueegg.com/Article/Crookneck/Crookneck.html
http://oureggbasket.blogspot.com/2013/04/wry-neck-or-crook-neck-understanding-it.html
http://www.browneggblueegg.com/Article/Crookneck/Crookneck.html
http://oureggbasket.blogspot.com/2013/04/wry-neck-or-crook-neck-understanding-it.html