By the time she is 15 (Actual Fifteen, not Nessie Fifteen), Renesmee is very tired of literature. She doesn't want to read about Victorian socialites and heaving bosoms, and she doesn't really care about which character gets the hero.
When her mother hands her a wrapped package that is very obviously another book (no doubt full of long skirts and ballroom encounters), Nessie smiles, grits her teeth and says thank you mama.
Later in the day she bribes Jacob to cover for her while she sneaks away to the local second hand book store.
(She tries to feel even a little bit guilty over trading the pristine first-edition for a ragged looking book of logic and mathematical problems from 1967, but the feeling just won't come.)
Three days later when her mother asks her how she liked the book, Nessie smiles and says it was beautiful mama and then goes back to a puzzle about spiders in a box.
(She thinks that it's one of the more frustrating puzzles she's ever read.)
At first it's simple, child's play, but then she realizes she's been letting her mind coast over the problem. She realizes that even though she's holding a pencil over paper she hasn't actually written anything down. She's half way through solving the problem and doesn't feel like she's done any work at all.
She breaks the pencil in frustration. And then tries again.
This time she records every step, writes down all of her math and then double checks every equation.
She gets the answer wrong.
(Beautiful.)