Started my daughter at 4.5 years old. She liked it since her dad did it. Got her a chimpmonk 22 then a shortened stock for my 10/22. Then got tired of loading mags and got her a Marlin60. Then a 257Roberts and a Browning buckmark 22 pistol before she was 10. Then a Ruger 9mm pistol and the girl laid claim to my mini14 and M1A. That is still in dispute and she is 20 now.
She also wanted to be a NRA life member after several years of Jr membership.
Each child is different. My ex-step-daughters are in their 30's now and still not ready to shoot.
A 30cal will reach out and touch them. A 50cal will kick their butt.
NRA Life Member
SCI, Manteca Sportsmen Club, Coalinga Rifle Club, Escalon Sportsmans Club & NAHA Member