I am trying to find an icon suitable to represent kids between the the age of 7 ~ 15.
So far I have come across this:
I was wondering if there is a better option out there?
In my opinion. Forget the option 1. It is for toddlers.
I thought Junior as a son that have the same name as the father. Posible terms, kid, minor, child, under 15...
For the icon, probably a head with a cap. I think that is representative of that range of age. (And maybe not pointing forward, but lateral or backwards)
By looking at the second I'm getting only male kids into my mind. I think you mean both male and female.
Try something which reflect both male and female kids, If you intended that one.
What others said are good and from my side I suggest something like kids foot print or some cartoon kind of kid shoes. They represent very well I guess.