Hi Newbie....Like you I am a housewife, 33, and I live in New Zealand. I have been a smoker for years, and can't even remember how it came to be. But to put myself in your shoes and think of what I would do is about the most help I can be to you...sorry.
To start with, I would not go to a school child to look for buying drugs. You must have some outside human contact? Just because someone doesn't look like a stoner doesn't mean they don't smoke. You will need to learn how to read ppl a wee bit, and then add cannabis into a conversation when the time is right. I'm not saying to come right out there and ask them to their face if they smoke or not, but just watch and observe their body language. You will know what to say and do when the time comes, its like a instinct or something.
But for your first time I do recommend that you start small and preferably with someone you know and trust.