I'm usually very wary of recommending a semi-auto to a new shooter, regardless of their age. The old rule "treat every firearm as if it were loaded REALLY means something with semi-autos, I've on more than one occasion had someone eject the chambered round, let the bolt ride forward, and hand it to me thinking they'd "unloaded" it (not realizing that with the magazine still in the weapon, the bolt picked up another round when it rode forward).

The 10/22 is otherwise an outstanding rifle. But, you're going to need to establish some discipline with the kids (and yourself) to keep everyone safe. When you're done shooting, or handing the rifle off to another shooter, make sure you unload it:

1) REMOVE THE MAGAZINE FROM THE WEAPON

2) Pull the bolt back, eject the chambered round

3) Inspect the chamber to make double-sure it's empty

4) On rifles with a bolt hold-open device, engage it

5) Carefully pass it to the next shooter, mindful always of where the muzzle is pointed

Might also think about getting everyone into a hunter safety course.