I understand that they got it from their Grandparents. You need to keep you pot locked up and please, don't let your kids help you in the garden. It's not really cool. One day that shit can backfire on you. Piss off your kid and they'll turn you in or rip you off! They might blab to the wrong person and next thing you know you're in hot water.
I have a niece who is 13. She never goes near my grow area and when she's visiting I make sure there isn't a bunch of pot laying around. Now that she's older I don't want her getting into my stash so I make sure she can in no way access MY medicine.