I've run into more range trouble with adults than any children.

Children mature at differing rates. Some are ready, some are not. Properly supervised, I see no problem interesting children early, hopefully before they become enamored in everything else vying for their attention. Since many areas allow no shooting except at ranges, we need to figure out how to accommodate the younger shooter.

"Think about how stupid the average person is, and then think that half of the people are stupider than that" - George Carlin