12 week old red star pullet from Ideal was found yesterday morning in the brooder unable to stand up. She was laying on her side and let me lift her up but struggled once she was held. She can use one leg but not the other one. It isn't a broken leg, there isn't any swelling, no wounds and it is as warm as the other leg. She eats and drinks and hobbles around. Doesn't act like she feels bad but seems upset that she can't get around. I could only think of Mareks but then she came from Ideal and vaccinated. Hasn't been around other chickens and is in a brand new brooder/coop. Anything else to look for or do for her? I've never had this mystery to happen before.