I'm Kathryn, and I play Katara k_waterbender from Avatar: The Last Airbender and Yvaine fallen_star from Stardust.
Katara is ninenteen, and Yvaine is thirty million years old, but she looks like she's in her early twenties or so. Katara has a lot of experience with teenagers, as she still is one technically, but two of her best friends from her world would be seventeen in the time period from which I've taken Katara.
I've never read The Chronicles of Narnia or watched the movies, but I'm okay with spoilers. They won't harm me. I don't even know when/if I will get around to watching/reading them.