This is a debut novel by an author who really didn't seem able to get into the mind of an eleven-year-old smart girl. So naturally this book has been nominated for awards which in turn spawned a trilogy when one book was far more than this particular subject ever merited. The problem is that the author is confusing genius with autism, and 'child-genius' with 'humorless adult'. Consequently she makes Millicent look like a moron rather than a genius, or to put it more charitably, she makes a girl who in reality would need some professional psychological help, look like she was dropped on her head at birth.
This is why I have absolutely zero respect for literary awards, and normally (when I have advance warning!), avoid like the plague anything which has won awards. Once in a very rare while such a book is worth reading, but in my sorry experience those books are a lot harder to find than the lousy ones, and the ones we typically are unfortunate enough to run across are for the most part pretentious and clueless drivel. For the awards people to constantly rate this garbage as merit-worthy only leads me to believe that they too, were dropped on their collective head as a baby.
The author makes the idiotic assumption that a kid stops being a kid if they're an especially smart kid. That's utter nonsense. They may see life through a sharper lens than most kids do, but they're still children with childish (in a benign sense) - impulses and drives. They still enjoy children's games and toys. They are not, simply from the fact of being more intelligent than most (in academic terms at least) an adult or humorless, or superior in a mean sense.
One of the most glaring problems with this book is that the main character has Spock syndrome. The Vulcan from Star Trek (original or reboot, it doesn't make that much difference) is supposedly of very high intelligence, but is routinely made to look like a clown because he simply (and inexplicably, given how much exposure he's had) cannot grasp human idiosyncrasies. In the same way, this novel is constantly telling us how smart Millie is, but what it's routinely showing us is how dumb and clueless she is. Worse, it's rendering her as borderline autistic in her rigid and utterly inexplicable inability to cope with human interaction. If she is autistic, that's one thing, and might have made a great story - one worthy of an award, but this author never suggests that. What she does is inexcusable. She presents Millie as lacking completely in not only social skills, but in any sort of clue as to how to develop them, yet she offers no reason - other than how "intelligent" she is for this deficit.
Millie's parents are the worst parents ever, since they seem utterly clueless in diagnosing Millie's condition. Fortunately it's a condition which exist only in the author's limited imagination. Millie is just one in a parade of one-dimensional characters, each representing an extreme of one sort or another, and the novel is so trite and so completely predictable that it's not only fails to offer an intriguing read, it also isn't even remotely realistic. These people are robotic, as simple and limited as the mechanical arms on an assembly line, each going through pre-programmed motions, and not a one of them capable of exceeding their programming, and living and breathing.
Millie meets Emily at the same time as she is forced into tutoring a boy she hates. Desperate to keep Emily as a friend, Millie elects to lie about her intelligence and gets herself into a situation that is unrealistic and which is dragged on for far too long. Predictably, Emily blows up, even though given what we've been told about her, this blow-up is out of character and comes off as false. It was at this point that I gave up reading this book, because I could see exactly how inauthentically it would continue to play out, and I lost all interest in it offering anything new, fresh, or credible.
Millie's extreme intelligence, despite that fact that we've repeatedly been shown that she can diagnose problems with the facility of a particularly sensitive and empathetic adult, is betrayed time and time again by the author as she makes her character fail in such diagnoses where it suits her, so that she disastrously assumes her mother's obvious pregnancy is a disease. The writing is amateur, rigid, inconsistent, and poorly done. I cannot recommend this. The only purpose it served for me was to once again provide a convincing example of how comprehensively blinkered are those people who give out literary awards.