Most Helpful Girl
I think children below the age of fifteen will like that. I remember that when I was a kid I was always interested in stories about characters a few years older than me. I don't know why maybe it has something to do with the fact that children always look up to people who are a few years older and want to identify with them, and when you read a book you also want to identify with the characters.
Most Helpful Guy
Of course it's OK. It would be a great book for teenagers