Is her neck facing the right way? Like not up or backwards? If so it probably is Wry neck. Try to feed/hydrate her by bringing her to the food and holding her over it, and wipe her bum area with a warm wet cloth just in case. If you can't take her to the vets yet just keep monitiring her and if...
Seperate them but keep them within sight of each other. In a few days, put them together for a bit to see if she's changed her behaviour. If not, keep them seperated till your chick is bigger.
You should take her to the vet, even if it's not major at the moment it could develop into something worse. Better not to take risks with young chicks. Also, is there a possibility of a bad gene? Ask the people you got them from if anything like this has happened with their other chickens.
