My kids have all helped in the darkroom (Mostly because they want to stay up late and help daddy).
A year or so after being given them, their camera of choice is still their Fuji Instax cameras (the girls each have their own). On our recent vacation to visit grandparents, they each took about 30-40 pictures. It seems to be the right combination for pre-teens of instant gratification, tangible product, and creativity in photography. When they are a little older and understand the limitations of the Instax, I'm willing to bet they will step up to 35mm.