Apply hot pack for pain relief. Ask her to use lumbar belt for back support and also helps in  pain relief. Consult physio for exercise progam which she can do daily at home.

Bhujang Asana -- Lie flat on your stomach, keeping the palms out, bend the neck backward, take a deep breath and while holding it for 6 seconds, raise the chest up. Release breath and relax your body. Repeat the exercise 15 times twice daily. Core Strengthening Exercises- Straight Leg Raised With Toes Turned Outward, repeat 10 times, twice a day.

Pain is not Symptom of osteoporosis or osteoporosis. In this age This is Common Consult with a Good Physical Therapist. He or She will Definitely Help you a lot.

Hello.... Osteoporosis and osteopenia are common in this age due to increased bone resorption... You should take her to orthopedic surgeon ...back pain is not due mobile phone or books... Improper sitting posture aggravates back pain... If she is obese she has to reduce weight.....