Butler has very consciously created a different kind of vampire, one who functions in different ways from anything else you may have read. For one thing, the Ina are an entirely different race from humans, and people can't be "turned" into one of them. They drink blood, but when wounded they need to eat meat. There's a lot of politics, ethics, and sexuality explored, which is pretty standard for vampires, but things like the total segregation by gender stand out as new and different.
Shori has the body of a ten-year-old girl. She's fifty-three, but in the eyes of the very long-lived Ina, she's still a child. Since they aren't undead, she has plenty of growing yet to do and will eventually achieve physical maturity. She is, however, a very sexual creature, and unlike other vampire stories, this is not implicit or explored through the feeding. The book is very straightforward about Shori having repeated sexual intercourse with Wright, which made me rather uncomfortable. I'm rather conflicted about my discomfort. For one thing, I think Butler made some very deliberate decisions here. She doesn't intend for Fledgling to be a comfortable read. She wants to challenge her readers, and making Shori a sexual being in a little girl's body is one way of doing that. On the other hand, this aspect of the book made me like her characters much less than I might have otherwise, and I'm not sure that particular side effect was deliberate on Butler's part. I have an eight-year-old daughter; I know what a ten-year-old girl looks like. Wright's sexual attraction to someone who looks like that is problematic for me, regardless of her mental or emotional age. He's vaguely conflicted over it in the beginning, but him being conflicted involves closely studying her naked body. He's somewhat influenced by her having bitten him, but this is after the first bite, long before he's been properly marked or claimed. Sex with children is not just a cultural taboo, and Shori is still a child by the standards of her own people, not just physically, but emotionally and mentally, even without her missing memories.
The decision to make Shori a child vampire at all has huge bearing on the story and even the tone of the book. There's something innately creepy about someone with the appearance of a little girl and the wisdom of a middle-aged woman. That she's physically a child also echoes Shori's ignorance, as she struggles to manage without being able to remember anything before waking injured in the cave.
Butler also explores issues of race here. The Ina swear they're beyond the human sort of racial discrimination, but Shori is the only one of them with her skin colour, and something bothered someone enough to get her entire family killed. Her skin colour is considered by some to be unnatural, an outward indication of the genetic experiments that made her what she is, but as with humans, her darker skin helps to protect her from the effects of the sun, making her burns painful but not lethal, as they would be for other Ina.
Fledgling ends abruptly, enough so I did a quick search to see if there was a sequel out there. As Butler died six months after the release of the book, there is not, but from everything I can find, she intended this to be a one-off. The denouement is very short, and is in fact included in the epilogue instead of the story proper, and leaves a few questions left open. Intentional? Perhaps. Enough to drive me batty? Definitely.
This is a well-written and thoughtful book, an interesting if not comfortable read.