Ya know, if you also grew house plants around the house, or even started garden plants in doors, or fruit trees then the mj would just seem like another plant. As for a reason they are in a special grow area is because they need a differnt situation to grow those types. Smoking around em is fine, just do it like u would a cigar or cigg.

Kids are so in tune to picking up on how you act and if u are trying to hide something from them. I've known people that worked in day care and they have said kids will tell them all sorts of private life stuff. Kid love to talk and they are very in tune to whats going on around them. They know more then we think they do alot of times. You can't trust em with a secret, they don't know better. I've tried to keep a secret with my 4 year old (nothing bad or illegal) but as soon as mommy came home it was the first thing out of her mouth even tho she knew not to say anything about it and agreed to it.

Make it all part of normal life and it should all be nothing worth mentioning to them.
Good luck