This book grew on me. At 50 pages in, I was ready to put it down and forget it. But that's roughly where it actually got started. It delved deeper into May and Pearl's culture, their personalities, and their relationship as the book evolved and I liked them both better and better as I read.
There are a lot of great questions that this book raises, and I look forward to discussing it with my bookclub. It was a very enjoyable read. More than that, it was decidedly uncomfortable for me in places when I considered my own relationship with my sister. I love when really good books make me consider how I'm living my life.
There are two things that keep this from being a higher rating for me. One is just the fact that it's written in present tense. I don't know what it is about that, but it makes the whole thing feel awkward for me. That's just my personal taste, of course, but that affects my rating. Also, and this is an important one with me, the book ends in a big "to be continued...." and I really don't like that. I don't even like it in hour-long TV shows. Good grief. Pick your genre and then work within it. If your book needs to be longer, make it longer. Did her editor say "nope, 300 pages is all you can do"? Again, that's personal. But that's a reason for the rating.