I guess I'm in the "general nerd" category, though I prefer to be called a geek. Lack of vitamin C can cause easy bruising, so get her to eat foods rich in vit C and bioflavonoids. There are other reasons that I guess a doc can diagnose or it can be a side effect of medications, etc. I used to do vit. C in powdered form (mineral ascorbates) but sometimes I just do emergen-C and eat handfuls of goji berries...yum.
I do a lot of homeopathic arnica... (Yeah, yeah, there's no scientific proof it works but it's a damn effective "placebo" then.) I used to use 30c (the kind you can get in stores) but I find that 200c and even 1m is a lot more effective. Sometimes I take arnica (or arnica/rhus/ruta) before class as a preventative. I still bruise up sometimes but not nearly as bad.
I'll also add that I recently read an article (not sure where) about how women and men feel pain differently. Women are better with prolonged pain and men are better at handling acute pain. So I know that as a woman I'll probably take a bit longer to recover from, say, getting punched in the face... However, there are advantages...like I think it's easier for women to learn how to use their entire bodies instead of muscling through things because most of us do that every day... Just a thought. It makes sense in evolutionary biology so I guess it's fair game.
Hope this helps!!
Also tell her to read this:
There is also the fightergirls forum which can be good for asking questions (except there's some really annoying trolls that nobody will kick out for some reason).
Hope this helps!!!