Karen Joy Fowler is an interesting writer. She launched her career in the science-fiction and fantasy field, earning some serious cred for co-founding the James Tiptree award with Pat Murphy along the way. Now she primarily writes literary novels (yes literature is a genre), or at least she ably disguising works of fantasy as such.
Sarah Canary is a perfect example of this sort of slipstream approach to writing. Fowler acknowledges this as well in the Q & A in the back of my copy. She says the title character could just as easily be an alien as the mental patient she is taken for throughout the book.
And as an aside, I'm greatly looking forward to her turn as guest of honor at this year's Readercon.