Lots of things you can try- a bag of frozen pease wrapped in a tea towel- 10 mins on, 10 mins off is good to reduce swelling and inflammation. TRY and keep her moving a bit- it will seize up if she stays in bed. Take paracetamol and if the pain is very bad, get some codeine from the doctor, and try and keep pottering a bit. Then see a chiropractor or osteopath. Doctors don't have time to deal with the many, many back problems they see, so they just prescribe pain killers, which don't deal with the problem. You can also get pads which heat up that you can stick to the area, which make it feel better. A TENS machine also can detract from the pain, but won't actually cure anything.