What has she done in her life? It might be catching up to her. Lack of D and B12 could certainly cause it. Lack of D probably means she's not getting enough sunshine and lack of B12 is either poor dietary choices, which can also lead to chronic inflammation over time, or a genetic problem that requires a particular form of B12 to help. Sleeping problems can lead to chronic pain. Bad posture can lead to it. Repetitive motion can lead to it. If it's arthritis, that would show in an X-ray. She's had the RA test, and it was negative. Some foods cause chronic inflammation, such as dairy, nightshades, wheat and sugar. Doesn't happen to everyone, but happens to many. Lots of possible causes, and the proper treatment depends a lot on the cause. When the docs you've seen can't find a problem, find better docs. If it's lifestyle, she needs to take a hard look at hers and try something new. This is difficult stuff to contain, but all the areas you mention are areas where things you did catch up to you as you age. Usually if no need for surgery is found you would be sent to physical therapy to see if the way she moves is responsible. Hope you find the solutions.