What Is Persistent Elevation Of Creatine Kinase Levels In A Teenager Suggestive Of?

I am wondering what would cause continual elevated CK levels in a 14 year old girl? We had an issue in March that resulted in rhabdomyalisis (sorry if misspelled) when we where admitted from the er to a week long stay in the hospital because her count was approximately 12,000 after 5 days and a lot of iv fluids we where released with a count of 400, two days ago we retested and are at 826. Local physician is running more tests and I am just hoping to possibly get another opinion what might be causing this. She is otherwise and active and healthy young woman