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:
http://tinyurl.com/y3jqy2
and this:
http://tinyurl.com/y68am5
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!!!