I have not been diagnosed with FM, my aunt has and i share a lot of symptoms (why i'm here, how i found the site). So this is mere suggestion. Melatonin.
Be sure to have her take 1mg as it is a hormone and, although there no known side-effects from prolong and/or high dosage use, it should be treated with caution. The warning is only precaution- i'm a bit geeky with science, examining natural cures and even fda approved ones with large skepticism- so don't be alarmed. I just know there there is so much we don't know, e.g. supplemental estrogen has currently been linked to causing dementia. Basically, just imagine how haphazard high school chemistry was and you've got a pretty good idea of the knowledge we have of our own body's chemistry.... Er. Sorry, ranting. It's not that big of a deal. I digress. [pushes up glasses]
Anyway, this has work for me greatly. I recommend everyone here to give it a try, not only for chest pains but also for fatigue. I can usually bite my tongue and just deal with pain but i got to the point of feeling like i was having a full blown "Forgive me, Lord!" pork chop sandwich revenge heart attack. Nearly passed out on my way to work. So that whole doctor recommended 'suck it up" mentality has it's faults when you can potentially drive off the road and kill a few people from pain. (...i think a lot of doctors have a bit of sadist in them anyway).
I had one little random burst of pain since i've been taking melatonin and it was only for about five seconds.
...now i just have to figure out the rest of the muscle pains.
I know i'm a bit of a crazy ranter, for this i apologize, but i hope this helps. Would like to hear feedback.