Does she spin in circles and tosses her head backwards when eating? Is the head tilted upside down sometimes? It can be paramyxo virus. You should seperate her from the others for the next 6 weeks as this is highly contageous. Don't let her fly free. After 6 weeks she won't be contageous, but might still have neurological issues. Supportive care is needed. Calcium and vitamins will help.