Kung-fu or whatever is a tool in my little toolbox of life. However what I believe your ladyfriend is failing to recognise is proper pistol work -IS- a martial art.
If Punk A-C have knives and you dont have any weapons, are forced into a dead end alley. You will have to closewith these punks and fight them. Now one mistake, mishap or even if you did EVERYTHING RIGHT. Your dead. Why? Because they have a weapon. A weapon is just a tool, you could spend 5 years training hardcore and your still gonna get screwed over hardcore..
now with guns
If Punk A-C have knives and you have your Steyr S40 , and you are forced into a dead end alley. You can draw your weapon and calmly instruct them that if they take a step closer you would be more than happy to drill .40 caliber holes in their skulls free of charge.
Heres another scenerio...
If Punk A-B corner you in a dark alley and one has a gun, and your unarmed. You cant really do much can you, even if you can successfully close with and fight Punk B punk A -will- put three in your back the first clean shot assuming he doesnt just close to jam it between your ribs.
Guns are tools, just because you have one available to you in a situation like above does NOT mean you will use it to kill everyone within a 10 block radius. Theres even a good chance you wont have to fire at all.