Guns are only weapon you need in modern RPG setting?

[Gnoman]

What makes a weapon suitable for children? Should I be looking for something that says "for ages six and up"?

Late to the conversation, but there's specific models of firearms specifically designed for adolescents. Typically, these are .22LR rifles or shotguns in 20-gauge or .410 that are built on smaller dimensions than an adult arm. The inherently low recoil of these rounds combined with the better handling permitted by the smaller size makes range accidents (often caused by a dropped weapon or the recoil taking you well off target) much less likely, while the lower power limits the damage such accidents cause in the event that they do occur. This makes them excellent training weapons for youths in families that hunt or own a firearm for other reasons.