Although she does say that she's glad DH and I can shoot and can teach her if the Zombie Apocalypse comes
Very important! 
I was initially adamant that my children wouldn't play with toy guns for various reasons. I ended up relaxing that stance a bit though. [toast guns, banana and lego guns...]
I didn't want them playing with something that in 'real' form hurts people.
My Dad has a firearms licence [he lives rurally]. My children have an understanding and respect for firearms, they have shown an interest and have been taught all the safety rules by my Dad.
One of my children was an army cadet and has learnt how to handle [dismantle, clean and rebuild] a weapon. The ACF has very strict rules on the cadets handling the weapons.
One of my main worries about them playing with toy guns, was that they may be seen and the toy guns may be mistaken for real weapons, triggering a response from SCO19. That may sound far fetched, but some of the toy ones look very real, also, some 'concerned members of the public' would miss the orange tip on the toy, put 2 and 2 together and come up with 5.
Funnily enough, when my children played with them, they were usually in the role of either armed police or soldiers. Never 'bad guys'. But, only ever inside the house due to the above.
I soon realised it is pretty much impossible to shield them from the idea of weapon based play, I believe outright banning of things just increases the attraction, my children have learnt about the serious side, but still also managed to play without and adverse effects.
Incidently, when I was a little girl, I was also very interested in toy guns and swords, it wasn't such an issue back then though, we were allowed to just get on with it.