In reply to JimR:
there is a growth plate in the hip and a couple more close by, she may have damaged one of these, with rest it may heal and I think checking it with a peadiatric orthopeadic consultant is a very good idea. If your peadiatric consultant said it would settle with rest then follow their advice. The few I have seen resolved with some time and rest without any problem.
She should be resting the hip and respecting any painful symptoms