If you DO opt for the handgun, go .40 cal (more stopping power than a 9mm) and -- especially if you have KIDS -- go SEMI-AUTO in something with a separate SAFETY (Glocks have none). While they're easier for the ladies to use, a REVOLVER is ALWAYS "ON" and if a kid gets ahold of it...
A semi with a full mag in the butt and an empty chamber and the safety latched is tough for a kid to operate. The slide spring on a .40 is probably too hard for a youngster to snap to chamber a round.
Whatever you get, EVERYONE who may someday have to use it MUST spend enough time at the range to become comfortable with it.
I DRILLED the FIRST RULE OF FIREARM SAFETY into my kids and grandkids: THERE IS NO SUCH THING AS AN UNLOADED WEAPON! If they don't learn anything else (but they DID), that one could keep them out of trouble.
Be safe -- and we all hope you NEVER need it.