I sense sarcasm, but it’s not unusual in many American houses. At that age, I knew where all of the assorted firearms and ammunition were kept. I knew where my father took off his holstered handgun (police officer) and where it was. It remained loaded, in its holster, and if I wanted to shoot it, that was fine. We’d just need to go to the range, and I’d have to clean it afterwards. At 12, I’d shot all of the firearms, barring one deer rifle that had a Monte Carlo stock cheekpiece that would have cut me had I tried it in my normal left-handed fashion.
The point is, they weren’t mysteries to us. Just tools. Annoyingly messy, loud, occasionally painful tools. (I don’t know who decided duck hunting should be done with a 7 pound, 12-gauge double barrel with no recoil pad, but I don’t like them.)
I don’t know if it was that way, in that particular 12 year old’s household, but it was that way in many rural and suburban households like the one I grew up in.