Bobert,
I'm prone to back spasms myself. She should probably be alternating with heat and cold (about 20 minutes each) and there is a good stretch wherein you put your foot on the seat of a chair or on the staircase about 2 or 3 steps up and stretch into it. NSAIDs taken every 4 hours (advil, ibuprofen, etc) unless she's on something stronger given by the doc. Sitting down is the worst position to be in. Best to either stand or lie down. And keep going to the bone cracker if it's helping.
Oh, and tell her I can empathize and it totally sucks!! Hope she feels better soon.