The Fairy Godmother: A Tale of the Five Hundred Kingdoms, Mercedes Lackey.
This fits in with my fairy-tale-themed books, but it is a real twist on them. Mercedes Lackey is very prolific and I know she's written other books based on fairy tales, but I haven't read any of them yet. I plan to, having enjoyed this one.
The story is set in the Five Hundred Kingdoms, where The Tradition is a sort of mystical force that is trying to make fairy tales come true. So if your life starts to resemble a fairy tale, The Tradition will work to make it seem more and more like one.
This is exactly what happened to the heroine: her life became more and more like Cinderella's.... Unfortunately for Elena, the Prince in her kingdom is only 11 & she is 21. Since Elena can't live out the story she was "supposed" to have, she has the chance to be a Fairy Godmother instead.
The novel is about her life learning to be a Godmother. It shows what they do and how they try to both help and subvert the Tradition. And, of course, there's a Prince. It's a fun novel. Her writing is engaging and I quite liked the characters.