Eh-hem... Everyone in the army has a weapon of some sort. Wheres yours?! (With this you can trick or treat the bank!;) )
LOL I couldn't find any toy guns that look like actual guns cause you know, they look like actual guns. So, I was going to bring my nerf gun but I forgot it. xD
You Americans and your guns
Normally you only carry guns in combatareas, guardduty or training (guns would only get in the way while maintining a tank, sitting at a desk, ...). The rest of the time (especially outside of combatareas) weapon and ammo should be safely locked away (in most armies in the unit's armory) and you rarely carry them without the complete combatgear (helmet, backpack, vest, ... which is not included in the costume). So not carrying a gun to the that costume is actualy correct.
In case you plan on wearing it again: Next time tuck the bootstraps into the top of the boot (otherwise they could get caught at obstacles in the field).
And if your friend gave you an elastic band for the pants, it is used by most NATO-militaries (incl. Marines and I believe the Army in the US) to roll up your trousers legs and have them sit tight over your boots (would also prevent that the pants to look to long for you).
Hm, Rosie is actually a very creative choice. The picture (not her name though) is even known in Europe. It became kind of an icon for womens rights after the war there (especially in the industrious countries like Germany when women wanted to join the factories workforce there too in the 60s/70s).