I've been asking myself this for a while, " What the heck is the age demographic of my readers? "  So what do I do? I plan it all out.
I really want to know the audience a bit more better, so comment on the one you are.

Elementary( Kinder- 5th grade )- Why are you reading this? YOUR YOUNG MIND SHOULD REMAIN PURE.

Middle School ( 6th - 8th ) - Seems about right. I do expect teens to sorta relate to this after all.

High School ( 9th - 12th ) - Wait,people around 15 - 18 are interested in this 12 year old's story? WHAT? WHAT THE * HECK * ?

College and further than that ( uh.. ) - " AND THIS..IS TO GO..EVEN..FURTHER BEYOND. "  * insert the internal screaming of a college student/ full on adult * .