conwict - what you say is true about knives and their use. But darkninja already said his girl has had some training in grappling, jujitsu and I think Karate? For her anyways the use of knife will be a natural progression if she just practices with it. She already has more skill than most men and women I know and with more than a basic skill and mindset she is more than qualified for a knife.
Your right on saying it's useless if you can't get to it. Of course that goes for anything, your gun is useless if you can't get to it, just because you have one doesn't mean your quick enough if someone jumps you quickly enough, or you can't dial 911 if you can't call someone.
That said she having the mindset and skill necessary for effective knife use, all she really needs to do is practice drawing and using it. Girl or guy it doesn't matter, a knife or a gun, both will deal damage regardless of skill. Of course the greater the skill the more accurate and deadly you become, lessening the chances of injury or harm towards yourself. As for the pink knife thing, for weapons the intimcy and close relationship and personal investment/knowledge of YOUR personal weapon does create confidence and better control of your weapon. How often would you let someone (even your best friend) borrow your gun and you always stress to them to handle it carefully, so you don't scratch or bang it around. How often do you say to yourself, "well he handled MY gun alright, shot alright groups, but he doesn't know it as well as me to get the most out of it." It's a all part of a mindset that owners of weapons have. When your KNOW YOUR weapon it becomes that much easier to use.
And a knife is a knife and can deal out some MASSIVE damage even from an "untrained" person. For me it's as deadly as a handgun. Most inevitably no matter how "good" you are you will always get cut. I don't know about you but I have only been in a couple knife altercations and thank god only got cut in one, the other ones my co-workers were there and the assailant backed down. But I did get a nasty 8 in long graze down my inner forearm, and trust me this guy was a joke but still cut me before I subdued him. Even a pencil or pen deals out major damage, I underestimated a guy cuz all he had was a #2 yellow pencil and that ended up 1 in deep in my wrist and part of it broke off in there. It's not like the movies where someone can ignore or shake off even a small cut. a 2 in puncture from a pen knife can kill you. That's the biggest mistake people make underestimating a knife no matter how big or who the assailant is, if they can touch you with their hand they can cut you. Judge me if you want but if a 5' 100 lb female rushed me and wanted to cut me with a knife I would have no hesitation about firing my gun, a deadly weapon is a deadly weapon no such things as "someone just wanting to wound you." My $.02.