I'm conflicted on this one. Maybe 3.5 stars.
Two sisters as protagonists with alternating points-of-view. In the end, the two narratives come together, and thematic strengths somewhat compensate for structural disconnectedness and other flaws.
The reading was always a bit disorienting. Some of that purposeful. One of those books where a protagonist has to make sense of their world, so readers get only glimpses of the world without explanation and nothing makes complete sense. It's necessary, I guess, on the one hand, for the sake of the character. But maybe if you used third person narration isn't of first, the reader could be given the rest of the details so that the world-building could be fleshed out early on. When this approach is taken by authors, I feel like information is withheld from us as an easy out to build suspense and surprise us later, but it's also an excuse not to have to fully explain your world and all it's rules.
Had worldbuilding been done properly and characters and their emotions been given more attention and development, this could have been a very strong book. A lot of potential, but ultimately lacking. Disappointing.