Sorry to hear about your daughter's problem. You should also get a urine culture done as PID is often associated with urinary infection and that is often neglected.
Also PID and UTI require a prolonged course of antibiotics (for at least 5-7 days).
If her pain is still persisting, she should also undergo an abdominal ultrasound
, which will give information about the rest of the abdomen as well.
Hoping for the best.