At first I thought she was ADHD, then I realized that most book characters.... Can in fact never sit still. Almost every character I think of, if they're told to stand in a corner and wait, they never will!!! They'll snoop the room, they'll get destroyed by a person or animal or something and go chase it, they'll be lead astray. No MC ever sits still!
I feel like she is meant to be written as someone who has ADHD though. "I forget my stuff! I oversleep! I don't want to, but I can't help it!" "It's so hard to sit still!" And of course, "once you lose yourself in a book, no one can shake you free!"
If she's not ADHD, then she's SOME type of neurodivergent.
Also, that's kinda what Theo is implying--that many of the heroes we hear about in stories would not be neurotypical.
"Somehow I can't envision ... that any would be content to sit quietly through class."
ARGEHFKJ