I had it when i was 12 yrs old....dr thought i was having growing pains til they ran some test after i passed out @ school. Sorry to hear your daughter has it and yes time will heal eventually. I have mitral valve prolaspe as a result and can't quite remember exactly how long the pain lasted but my legs really was so painful that it hurt to lay/sit still for a few minutes. Please get an 2nd opinion, couldn't hurt.