I started my oldest daughter with a youth model Daisy bb gun at age 5, let her shoot a .357 revolver at age 12. The maturity/age is different for every child.
I waited till my daughter was in her teens. Took her dove hunting and she outshot her boyfriend with my 20 gauge.
Oops!
First time she shot a rifle she shot a 2.5" 3 shot group with my SCAR.
At 200 yds. She was supposed to shoot the 100 yd target but looking through scope she accidentally shot the 200 yd target. I was looking through spotting scope and thought she was missing so I was coaching her on trigger pull. Lol.
She picked the SCAR over my bolt and AR .223's caused it looked cool.