Rather than start another thread on the topic, do you mind if I ask a question here about my own WIP? (And in response to yours, I think just making your MC 17 or 18 would be an easy fix)
I think my book is going to be aimed at kids around 10-14; while the book is not super-complicated, it isn't a straightforward, happy-go-lucky MG either. My MC is eleven and her two male friends are 12 or 13. Is this too young?
The thing I'm thinking about is that once girls hit their teens, all they think about is boys, and there is going to be no romance in this book at all, it's an historical adventure/ thriller. I really want my MC to be a child, not a young adult. I mean, by the time I was 12, I was the same height and not far off the same build that I am now, and strangers used to think I was 17 (ok maybe I was an early developer, but still).
I remember Lyra in His Dark Materials was ten or eleven when it began, even though the book was, I think, far too complex for readers any younger than that and probably even of that age (I know I spent ages going Duh, what exactly IS dust?). Obviously, I am not a genius like Philip Pullman, and that was a very successful crossover book too.
What do you think?