I suspect that I am fairly biased here, because as I said I don't agree with the 2nd Amendment, it isn't safe and scares the hell out of me. Florida passed a law that allows people to shoot first if they feel they are in danger, I wonder how many paranoid people are going to start shooting the neighbors.
My problem with the girl shooting the guy wasn't that she was going to hurt herself or others. The fact is, you are teaching her that weapons are "fun" and good, while weapons are, IMHO, not either of these things. I don't plan on ever owning a gun, because I don't think they are good things. Sure sure, what do they say "Guns don't kill people, I do". Well guns make it easier. Teaching a little girl that they are good just inforces the idea that it is okay to shoot someone if you feel they are bothering you.
There was a store in Waco, TX, this was a number of years back, but a dude was stealing a can of spam from the store, the store owner used a .22 shotgun and killed the spam thief. Is this justice? I think not!