My daughter had to stop during a sprint race at sports day on 8/06/2015 due to a pain in her thigh, she has been limping from last week still sore

See her doctor: She may have a pulled groin or other issue. Her doctor will give her a proper diagnosis and treatment as well as order any needed tests. Hope she feels better soon.

Muscle injury: This muscle strain with possible microtears May take weeks to heal. If it's a hamstring muscle that was injured,it could take longer. After resting it for 10-14 days, I recommend an evaluation by a physical therapist if there is still ongoing muscle pain and tightness.