Nine years of age is a bit young for a first shotgun, in my opinion.
thanks for your input; i'll take it under advisement. it didn't have any negative effect on me that i've ever been able to determine. i guess i was lucky having the dad i got who didn't impose me with a bunch of low limitations. and i was shooting his 1100 20 ga while i was still 9 or possibly just after i'd turned 10 and recoil was not an issue at all. i still liked shooting "my" gun but i realized i'd have been better off w/ a 20 than a 410. i've never noticed the bolt locking back causing any undue recoil. certainly no more than any fixed breech gun.
i'd been shooting a 22 since i was 4 (yes 4; he'd hold the gun and let me aim and pull the trigger) and had a BB gun by the time i was 5 and had shot some shotgun of his before i had "my first shotgun" so he already had a pretty good idea what he was doing in giving it to me.
i suppose technically i was probably 9-1/2 or so. it wasn't a birthday or Christmas present. it was just a present.