Hi! This is my first day on this site so I do not know the full story behind the rib pain. I am a physical therapist and have dealt with rib issues before. If tests are all normal, my first instinct would be whats known as costal chondritis. This is inflammation of the cartilage between the ribs. A good test to determine this is increased pain with deep inhalation. This expands the lungs and ribcage. This condition does not show up on x-ray. If this is the case, and I am only taking a stab at this, your daughter is no danger. The longer she stays inactive the worse the condition can become. She should resume normal activities. They will be painful at first, then should lessen as time progress's. This inflammation can restrict normal lung and rib function. It must be stretched and this means breathing and moving. Let me know if this is helpful.
It is of utmost importance to rule out an uneven rib cage and/or scoliosis.
Left untreated, it can lead to chronic back, shoulder or rib pain and potentially lung and heart complications.
So should this be the case, your daughter while still growing (assumption) could benefit greatly from wearing a back brace, in order to stop the progression of the damage.
Did she get an MRI, bone or CAT scan?
If yes, do you have the radiologist's report?
Because of the limited information given, I'm unable to offer you any further ideas and suggestions.
Best wishes,
Niko