Harmony is based on interesting themes, of how challenging it is to have a child on the autism spectrum (perhaps, the diagnostic is uncertain), and how desperation can bring parents to unproven gurus, and in this case to a strange summer camp to work as an unpaid slave. There is also a clever plot centered in the set of children at the camp, perfectly crafted to exploit the fears and decision making of tweens.
The chapters that carry the story are written in the voice of the mother or the younger, neurotypical daughter. The mother’s chapters are written in a rather irksome second person. The daughter’s chapters improve over time; they start with a slightly wrong, too-old voice in my view. And the story seems not to be able to soar above the promise of its themes, especially the trite ending.