Fledgling question

Yeah, that bit skeeved me out too. Butler gives us a few hints as to what is really going on there, but just so as to allay your concerns, (view spoiler)[your first impression is quite right. She's an older person in the body of a younger person—or, rather, she ages much more slowly than do normal humans, so the character is chronologically fifty-three. (hide spoiler)]. So, she's kind of flipping the script on that one a bit.

Vampire/victim age discrepancies always give me pause. Hopefully, you'll not find a (view spoiler)[fifty-three (hide spoiler)]-year-old having sex with a man in his twenties as creepy.

I read this book as part of the GR bookclub I'm in,
Sci-Fi & Fantasy Girlz, so for a fuller discussion have a look at: https://www.goodreads.com/topic/show/...

This is far from Butler's best work.
I'm nevertheless fond of the book because I like reading her but often find the nasty stuff in her books overwhelming. There's no apocalypse in Fledgling, people don't tear each other into pieces over scraps and instead of the patriarchal sociopaths she loves to write about, you get to read about people who actually care for each other.

I don't think it makes a difference how old the vampire child actually is.
What does make a difference is that this child is a man-eating monster who uses mind-control drug on her sexual partners. She's not a victim but the predator.
This SO not like pedophilia!
Many read the book as a power/sex fantasy and/or as a revenge fantasy: the reader projects themself (or their younger self) in a character who looks like someone who might be a victim but actually hurts and kills people, does whatever she likes and has sex with whoever she feels like.