Another reason for her behavior could be possible Mareks Disease. This can resemble limberneck. Did she have a Mareks vaccination? For botulism, you can give an epsom salt or molasses flush to flush out the poison. Epsom salt flush is 1 tsp epsom salts in 4 oz water-give this to the chicken...
Welcome to BYC. I would worry that she might have eaten something that has made her sick. Botulism or limberneck is a disease that chickens get when they eat rotting fish or carcasses of animals, maggots, vegetation that has spoiled, and even pond mud. The symptoms start weakness in the legs...