Ideally, re the ''four rules'' you start em as early as possible!
When I started serious shooting around 1980 .... and compos etc ... my two were about 5 and 4. For quite some time it was just a case of ''Dad has gone to range'' .... or ''dad went out to shoot rabbits''.
The turning point tho came when they got to accompany me to the range ... spend the day there with me... watching at first for quite some time and then over the years ... they got to try simple stuff like .22lr rifle . and then .22lr handgun. By time they were both in teens .. they could shoot most of my handguns.
When my son was approaching 20 he was at the range on a day when we were doing a PPC compo ... I shot my detail and, cos I had enough ammo loaded .. my son did the same shoot. First time shooting the course of fire (with my 686) but oh man was he ever a natural .. and he claimed much of that was thru early familiarization too.
My son now hunts and has a GP100 ... poor fella has way too little time to enjoy shooting tho, like his old man can!! If I could ... I would have bought them their own guns way back.
My daughter has hardly shot at all over many years but ... joy of joys .. when she and her old man were staying last year ... she shot with all sorts and handled the P97 like it grew in her hand. Pride? I'll say!
I'll even see if I have the pic of her I posted ages ago, with P97 ... many have seen it but ... it makes this ole fella proud ... the intro to guns way back paid off handsomly.
I might add ... she lives in UK and so shooting is out. Were she here, then I'd make a point of buying her a gun ... but instead just look forward to her next vacation visit when again we will share the joys of shooting together.