When you grow cannabis you get to enjoy the fruits of your seeds. Whereas with children you have to feed them and make them self sufficient in life and in the end you are giving up part of your life away, assuming your kids don't repay you.
Feed them, lead them down the road to being self-sufficient and in all goes right they will help through old age. Help buy seeds, help lift those heavy pots of soil, and most importantly help by recognizing their parents gardening abilities and encouraging the grows.