At age 12, the only type of computing that kids are interested in is video games. If you want to tell a group of kids about your job as an IT professional, you have to somehow frame it within that context, even you don't actually design video games. So, explain that you start with a conceptual idea and then storyboard it. At a bare minimum, it involves programming and graphic design. That's the cool part, and some kids can do it better than most adults. But for a video game to be successful in the real world, to turn it into an actual job that pays money, it also involves a group of people teaming together, capital investment, and marketing.

Really, IT is an easier sell to kids than accounting or proctology.