My first 2 .22s were...
a Marlin 101 (nearing the century mark and still a great shooter)
The Ar-7 explorer.
The Marlin built my patience being a single shot bolt action, but I have a very large soft spot for the AR, my first semi.
My 8 year old is getting the new Henry built one for her next birthday, maybe Christmas (she's on the 101 herself now). They've added a rail for a red dot or scope.
The simple build/takedown (screw barrel on, screw stock on, insert mag, go!) starts them on maintaining their gun at more points, the featherweight ensures they won't be begging you to carry their gun at the end of a longer hike, the ability to float is a good idea with kids in general.
The accuracy is just a perk ^^, I used to pick pine cones off the tops of trees. (before my old man caught me and taught me that falling bullets can kill people)
Remember high velocity ammo only, it needs the kick to cycle properly.