I would suggest finding a book that teaches beginners the rules of chess. Show them the rules fully, and let them play.
If they want to play more, introduce them to chess.com's website and the possibilities of playing different chess time controls.
If they ask how to get better, tell them about studying and reading chess books. If they have computers, they are able to learn and practice online.
I know that they could work on some basic chess tactics, that chess.com kid's site has to offer.
There's also downloads in the resources tab, and under the fun tab, you could expand their knowledge by making it fun using them.
Not sure if this helps but good luck. You have open doors for young minds.
I'm an English teacher and a couple of my 10 year-old students recently asked me why every time they saw me on the computer in the staff room, I was playing chess. I told them that I loved the game and that it's fun and great exercise for your brain. So, they asked me to teach them.
I brought my board today and taught them the names of the pieces in English and how to set up the board and how each of the pieces moved(I left out castling for the moment). They played each other for about 20 minutes and seemed to really love it. They asked if they can come to the office again tomorrow.
But I was wondering. How should I teach them? Do I let them blunder around forever? I'm not trying to make mini GMs here(not that I could, even if I wanted to) but I do want to help get them off to a good basic understanding.
Anybody got any thoughts/suggestions/memories from when you learned?