I'm runing OSx86 on a Toshiba notebook. Issues: basic trackpad drivers with no side scrolling, tap, etc. No dynamic speedstep for lastest OSx86 release. Other than that it runs fairly ok, I had to fiddle around with gma900 drivers and other things quite a bit.
I would only recommend it if you like fiddling around or want to try out OSX before buying a Mac...
Dell laptops have issues with recognizing both cores even on the latest kernels, so that's a problem. Video drivers aren't exactly easy, but they aren't that hard. Intel wireless is NOT supported at all currently.
if she just want to get away from the windows interface and to something else, Ubuntu might be a good (free and legal) alternative without forking over an arm and a leg for hew hardware. a propery configured gnome setup does feel "osx-ish" to a not experienced user.