Oh good grieffff!!!

I had assumed it was for an adult. Sorry about that.

Like Pete I strongly support bright children with curiosity about technical matters.

Just at the moment I am a bit spent, having been replying to a highly qualified adult, which is hard enough work in its own right. But if you (as I suspect from the tone of your writing) as we always have done in our home, refuse to talk down to children, then you should be OK if you can avoid going more than one step at a time beyond what she already knows. If you get stuck, come back and we will do what we can.