It really could be so many things. Bursitis, tendonitis, arthritis, neck problem, spine problem, artery problems etc.
She needs a correct diagnosis before she gets any treatment. I know it's a pain in the butt to run to different doctors but that is what she's going to need to do.
I see you say the ortho has not recommended surgery. In his opinion, what is the problem? Has he ran any tests? It doesn't seem like he's helping her or from your post, that he even knows what's wrong.
Try not to spend too much time and money dealing with ineffective doctors. A major medical center or a geriatric ortho might be her best bet. No one should have to go around in pain all the time.
Good luck to you both. Hope you find some answers.