Has she gone shooting? I know we started this convo but I'm not sure how it turned out. Is she from a liberal background? Not that there's anything wrong with that...
The only people I know who are anti-gun are fairly wealthy and have never had to worry about a) killing their own food or b) had to live (not work or shop, but live) in nasty, high crime areas. Like my delightful neighborhood haha! If it isn't too strongly ingrained, I think all she needs, apart from your expert and finely honed sense of when to push and when to feign retreat is to shoot a firearm that balances a feeling of obvious power and ease of handling. So, no S&W 500 just yet... The .380 might be perfect. And if you think that would work, I will lend you mine for a month. Seriously. Win her over now!!! haha