Kelly introduces each chapter with quotes from Darwin's Origin of Species, guiding the reader to apply scientific processes to Calpurnia's everyday life. She evolves in the same way other organisms evolve, and readers observe her break free from the norm as she studies the potentially new "moo-tant" species.
My favorite part of Calpurnia is that she isn't completely anti-everything expected of young ladies. She's a bit of a Liz Lemon:
She may put up a fight against knitting, but then she realizes she kind of enjoys it, and that's okay. Being so completely against all of these things would make her character feel forced and give off a false indication of what a science-serious girl should be.
Bridging the gap between various subjects is a fun task for librarians, particularly school librarians, and Calpurnia Tate offers a lot of potential for English-Science, English-History, and/or History-Science pairings. If anything, it could be used in a fiction section in a science or history display. But if you're going for more elaborate programming, it's time to brush off your scientific classification skills, classify characters into different species, and invite students to do the same for other characters, either from Calpurnia Tate or elsewhere.