The Black Tides of Heaven, by Neon Yang

First in a series: magic, prophecy, family guilt trips. I really liked the concept of a race whose gender is literally undecided until around when puberty hits, at which point they can choose to be male or female (or perhaps neither?), and their body will adapt to their decision. A pair of powerful twins need to figure out a path forward through political unrest, their manipulative and cruel mother, and their bond with one another. I like show-don’t-tell worldbuilding but this one was a little too vague sometimes.