I'm sorry, but this little morality play doesn't seem (to me) to say anything nearly as much about "gun control" or "Second Amendment rights" as much as it does "You're never as fucking smart as you fucking think you are so you need to plan for that".
Because there's really only two ways I can see this playing out:
1. Li'l Jocko reaches into Mommy's "specially designed" pistol-carry purse, extracts her hogleg, jacks back the slide, releases it, takes up a solid, two-handed firing position and puts a round into Mommy's brain housing group (all without Mommy either seeing him do all this or hearing the sound of the automatic pistol action being worked - an unmistakeable noise for someone who was supposed to be all Miss Idaho NRA as the mommy-target is said to have been) or
2. Now-deceased rocket scientist was wandering around Wally Mart with a freaking round under the hammer in violation of every common-sense rule on firearms safety ever thought up and Rule Number Zero for any sort of firearm, thus allowing her sprog to simply slip the bullet-launcher out of her clutch and put one in her ten-ring, easy-peasy.
Believe #1 if you dare, but I gotta go with #2. Which pretty much goes to show you that you can be a valedictorian, scientist, wife, mother, and firearms aficianado, and if you fuck up Rule Number Zero for a tenth of a nanosecond chances are you'll wind up dead as mutton.
Which, in turn, reminds me again that waaaayyyyy too many people can get their little paddy-paws on firearms who shouldn't go out in public with anything more lethal than a fucking licorice whip.