I can understand your concern.
The problem needs to be evaluated as you have provided very insufficient history.
It could be a deficiency of calcium and vitamin D3 also.
Ask her to take a glass of milk daily before bed, exposing the body to sun for atleast 20 mins before 12 will help in getting vitamin D3. Tab. D3 must 60k once a week.
Tab. Aceclofenac 100mg twice a day after food for pain.
Do core strengthening exercises daily. Yoga will also help.
Consult a orthopedician for further help regarding this condition.
Dr. Anil Kumar Jain.