what size of what??
No.
size 12 or 14
I'm 13 & I wear them. You should wear whatever you feel comfortable in.
The size that fits their feet!
Should wear 7/8 or meduim
No you can not.
A 12-year old girl should wear a size 12/14. If the girl is tall, she may want to go up a size so things will fit better.
8 inches. If you're below that, shame on you.
6'4"
Yes.
an 11
Whatever shoes fits their feet.