It's tough, stylinsam, to sort this one out since true heart problems in women can present so differently than in men. My addition to the heart horror stories: a mate's mum complained that her bra straps were too tight all of a sudden. We told her to lay off the flan. But she was, in fact, having a heart attack. (Treatment received; she's fine now.)
Gleaveyweave's on a good track: it could be something like what I have, chest wall syndrome. It's an inflammation of the chest wall that I thought was angina - it feels like the pulling across the chest and is pretty much constant, with different activities increasing the pain. I got it last year when I started weight training. It's annoying. NSAIDs help.
But she's just got to rule out the heart stuff first. Of course, she's also got to realize that she's worth the efforts it takes to sort this out. Good luck!