callalily,
The best physician to take her to would most likely be an orthopedic surgeon. The orthopedist can perform a thorough exam and be able to treat most musculoskeletal problems.
If she goes to a primary care provider, she will be given NSAID's (if she can take them), maybe some physical therapy, and then a referral to an orthopedic surgeon. So, if she has already tried the OTC NSAIDs, you can probably skip the primary care provider.
There are many things, other than arthritis, that can cause pain around the hip region. This is another reason to see someone who can do a thorough exam.
Hope she feels better. Good luck.