It's a pretty wild thing to attempt enforcing here. It's not like kids don't actually immediately find the work-around for this stuff. And this one doesn't appear to be anything more than an age tied to the user account of your OS. Simple to move around.
But this "for the kids" crap is always lip-service at best, and something more nefarious at worst. The US foster care system is a prime example of that kind of thing gone rampant.