Sorry that you are not getting the answers you need. There is more info from people who have posted on wry neck threads than scientific information in publications. You might go to the top of the page and search forums for articles. I have only seen it in one chicken, an 8 year old rooster who...
Wry neck (torticolis) is just a symptom. It can be seen in chicks with a vitamin E or B1 thiamine deficiency, from a head injury, and is seen in a few diseases that affect the brain, such as Mareks and Newcastles. Some cases do not get better, but hopefully, in time she will. Was she vaccinated...