Ahhh, that is nice of you to foster her! Well, some times you just get a cheeper. As long as she is eating and drinking and acting ok otherwise, I would not worry. She'll quiet down after awhile. Depending on your set up, you could try to turn off the lights where the chicks are. That sometimes settles them down quicker. So far this season I have had 1 chicken cheeper chick and 1 quail cheeper chick. They both settled down at night and got to cheeping during the day. After about a day for the chick and 2 for the quail they settled in and stopped cheeping. I cheked them on a regular basis to make sure they were not distressed but they were ok.