All good comments. I am assuming that the girlfriend is not very familiar with weapons specifically hand guns. You and her both really need to take a gun self defense course before you go looking for guns for self defense. From the limited information I would suggest a revolver not an auto. If that emergency ever arises and she is in panic mode and the adrenalin is flowing and she is scared crazy you don't want to be worried if the gun is cocked or not, theres a round in the chamber and you don't want to be messing with a saftey. You want to just put your finger on the trigger, point and shoot. And you sure as heck don't want to fire from inside a purse. Again it sounds like you both need to aquire a lot more information before purchasing a handgun and a course is a good starting point. Most gun stores either have or can direct you to handgun courses.
Hunting, fishing, Labrador Retrievers and at the end of the day a glass of Forty Creek Barrel Select Canadian Whisky - Life is sweet