Well, at this point, I doubt that the 3-year old can rack the slide on a 9mm yet, and you can make the 10-year old keep his paws off the gun, so a loaded magazine in the pistol is OK as long as you leave the chamber empty, WHEN YOU ARE AT HOME AND CAN ENSURE THE 10-YEAR-OLD IS NOT DEMONSTRATING THE GUN TO HIS BUDDIES WITHOUT YOUR KNOWLEDGE!! A pistol kept in CONDITION 3 is OK as a home defense arm. Keep it locked up when you are not at home.

If you have any doubts about the ten-year old, get a M1911A1 type and install at least a 24 pound Wolff recoil spring in it. He cannot load that!!