Low back pain and leg pain could be due to spondylosis and nerve compression. There is extra bone growth in spondylosis that compresses on the nerve. That can cause back and leg pain. She needs a thorough evaluation, may be an MRI and depending upon the severity of problem further treatment can be started. In the meanwhile she can take hot fomentation, mild anelgesics. Lifestyle modifications in the form of a few days rest, avoid bending, avoid lifting weights, some anelgesics. If pain still persists then consult a Neurospine specialist.