It sounded like Piriformis Syndrome to me and why I think getting the books will help. There are many, many causes for sciatica and she probably needs advice from a medical professional who deals with biomechanical issues for cyclists. The inflammation could be caused by jarring on the saddle and/or leg length discrepancy.

http://www.answers.com/topic/piriformis-syndrome

http://www.americanrunning.org/displ...rticlenbr=2056

As Baker says, "Pinched nerves in the back are the most frequent, but not the only, cause of sciatica. Occasionally, the nerve is pinched in a buttock muscle, the piriformis, rather than in the spine." This is why you must find out where the nerve is being pinched.