I'm all for letting her see the home invasion stories, the one about that little gal in OK who defended herself and baby (stress that the cops came 20 minutes later, remind her that when seconds count, the cops are only minutes away). Do you have kids? The ONLY way the average small/weak female can effectively protect her children from multiple large, violent attackers is with a gun. Home invasions happen.
My second wife thought she was scared of guns. Was a little surprised that my pant "clunked" when I undressed. Turns out, considering it all, she'd been exposed to A**holes with guns and it was armed A**holes she was scared of. She went shooting a bit, owned a few of her own, never got hot about them.
My present wife loves knives, guns, lifted 4x4s. An ex-cop veteran of actual violent encounters, she's ALL for being armed.
But something I always did for the second wife: Make sure it's fun and has no bad surprises. Nothing turns a wife off like a painful surprise. Make sure she's got good ear and eye protection. Let her see you shoot it. Let her see the expected recoil, both holding tight with both hands and holding loosely with one hand. Let her decide whether to try it. Almost nobody fails to enjoy a little plinking with a .22.
Of course, all this is assuming you can get her to the range or to a firearms safety course.
I suppose a subcription to Women & Guns wouldn't hurt, maybe get her a couple of Paxton Quigley's books.
If you can get her to absorb Cooper's Four Rules, talk her into a safety class, it's a good idea. Tell her a person may not like cars, but Driver's Ed teaches you how to behave around then and how to handle them safely. A basic gun safety class makes sense even if you're not a shooter; sooner or later you'll encounter a gun.
I suppose changing wives is out ? ? ?
“The police of a State should never be stronger or better armed than the citizenry. An armed citizenry, willing to fight is the foundation of civil freedom.” Heinlein