You don't have to get rid of the chicken. It is probably upset because of the move if it did not have it before. However, you should probably separate that chicken (put it into a dog carrier or another cage) and move it away from the others for awhile until she gets better. Make sure she is well hydrated as well. Watch the others to see if they are having any similar symptoms.
Another thing is, has the water changed at the new place? If you move to a different city or are on a different water source like a well or move from well to city water that could possible upset their digestive systems a little. I would still seperate her and watch her for awhile just to make sure though.
