I started both my son and daughter at 3 yrs. old...he's 8 now and loves to shoot, my daughter is 4 and she is an absolute nut about shooting....she's asks everyday, most of the time more than once!
I ask if they want to shoot,if they're not already asking me. But I never, ever force either of them to shoot with me.
Keep it fun...they like to see results, not just arrows stuck in a target...targets they can knock over, make noise, or break, like balloons, are some of their favorites....
Both of mine started out with a Black Rhino M-35
9#@ 18".....