...okay if she wants him to draw things he can draw things, but what - oh, she probably caught him thinking about his father.
He is not much of an artist but he manages four stick figures, each manipulating an element. Stick figure with hovering rock: "Earthbender." Stick figure with streams of water: "Waterbender." Stick figure with flame blast: "Firebender." Stick figure with little swirling breezes: "Airbender."
New pair of stick figures with associated elements: "Father, firebender. Mother, waterbender." Ensuing family tree: "Brother, firebender. Sora, waterbender." Brother gets crossed out. He's not sure if she's still reading his mind, but if she's not he has no idea how to explain 'my father strongly implied when I was growing up that I had an older brother who was a firebender but also an incorrigible troublemaker so Father killed him and started over', so he's just going to move on. Here is a bad drawing of the house where he grew up, on Ember Island surrounded by lots and lots of lightly tended wilderness. Here are father-stick-figure and Sora-stick-figure standing next to the house.
New page: Sora-stick-figure doing various badly drawn tasks like cleaning his room and reading books and learning firebending katas for no reason except that his father wished he'd been born a firebender instead. Father-stick-figure watching approvingly as long as he gets it right. Sora-stick-figure dropping a plate and breaking it. Father-stick-figure yelling. Father-stick-figure throwing fire blasts at cowering Sora-stick-figure.
He looks up from the page and over at Pradnakt - is this a sufficient explanation?