Muscle pain is near the top of my list when it comes to symptoms of my ME/CFS. My muscles are chronically tense with frequent spasms. I always have pain in a few places, but other spots emerge, stay a while, and eventually go away, only to reoccur in a new spot. Since your description of her pain seems reminiscent and no one else has mentioned any site specific treatment, I thought I would put in my 2c.
My chronic muscle tension and pain emerged about the same time as the debilitating fatigue (my first symptom) of ME/CFS. The severity crept up over a few years until I was pretty miserable all the time. Docs tried a few different muscle relaxers and referred me to physical therapy more than once. I also started taking supplements suggested for muscle relaxation. None of those efforts had any effect on my pain level.
The first treatment that offered any relief was massage therapy. My pain tolerance is pretty high and those sessions were rough, so I'm doubtful this approach would be possible for your wife. However, when my therapist passed away and I could not find another, I decided to try chiropractic. I should note that none of my six doctors had ever suggested this as a possible treatment option and I had always been skeptical about such providers, so I never asked. But at this point I was so desperate for relief that I was willing to try just about anything. And so, I made an appointment and it just so happened that the clinic had a nurse practitioner on staff and she offered trigger point injection (TPI). We quickly learned that without the TPIs occurring first, little "adjustment" was possible on my body. And so I began having both at every visit. While I obviously can't really separate the effects since I always have both, I do know that the muscles we target with TPI start to relax immediately. They hurt, but not for long. And so now I know that if I attend faithfully every two weeks, my level of chronic pain is significantly reduced overall.
Good luck to you and yours.
Laura