As odd as it sounds, I have found for my deepest hip/joint pains, ice on my very low back has helped the most. I have had bad enough hip pain to prevent me from walking, and sitting was a whole new challenge, although laying down wasn't much better.
I have discovered though that sometimes I need to use heat instead - and I believe the difference is the source of the pain. If it's caused by inflammation, ice is the only thing that helps. If it's caused by muscle/tendon tension, that's when heat actually helps.
So I would suggest she try both of them.
Inflammation can be caused by having Lyme, which is an inflammatory infection.
Herb only treatment for Lyme & Bart ended 12/11 - no active symptoms for 2 yrs -Herb only treatment for Babesia ended 12/12www.healingwell.com/community/default.aspx?f=30&m=2977364
Had Lyme, Bart, Babs, RMSF, Ehrlichia, Myco, Anaplasmosis, EBV
New Lyme case 8/2014 - Healed 1/31/15 - unknowingly had Asymptomatic Babs and Asymptomatic Bart, being treated now though (2/2016)