These are gonna be a series of short letters, written by Jon from the Wall to Arya which he never sent. Just a little something that came to mind. Enjoy.
Arya,
It's cold here, colder than I thought it would be, but it's beautiful at the same time. You and Bran would love it. There's so much to climb and look at that the coldness doesn't seem so bad. I tried to picture you in the south, in the sun and in dresses, but it just doesn't fit. How are you, little sister? I hope you haven't caused to much trouble. I heard about Nymeria and Lady. I'm sorry. It seems wrong that I'm here and you're there, but this is the way it is now and will be for as long as I can think.
I won't send this letter, I know, but it's nice to at least imagine sending it. It wouldn't be proper for you to be receiving letters from a bastard brother on the Wall, even one who is your brother. We're meant to renounce all family, all names, all land when we take the black. I'll be saying my vows soon, but I just don't think I can renounce you all.
Until next time, little sister,
Jon.