Really sorry to hear that happened, ammo. Never brushed up against any experience so violating as that, but had experiences similar enough to understand some of the sense of non-security/general offense.

Would echo what rd95 said re. buying a gun as a reactionary measure. Do you expect it to happen again? And if so, do you expect enough of a grace period to learn how to safely handle and own a firearm, if there is any such thing? Have you exhausted all other precautionary options? Security system, stronger locks, automatic lights?

My objection to guns is largely philosophical, so it seems wanky to expound here in light of your significant other's and your trauma. I will say that with three kids, I'm fairly certain that the risk of accidental death would outweigh the chances of 1) a home intrusion and 2) a successful fending off of the same.

Besides that, can only add that I hope it doesn't happen again, and I hope never to experience anything like it either. I'd like to think that if it did, it wouldn't shake my value system, but who knows. Sorry again.

EDIT Also, and I guess this should've come earlier- what does your girlfriend think? It happened to her, after all- shouldn't she ultimately have agency over how she controls her sense of security in the future?