Zahler, Diane. A True Princess.
Lilia has been fairly happy being raised by a kind farmer who found her floating in the creek, and is great friends with his children, Kai and Karina, but when the farmer's new wife wants to sell her to a cruel man, Lilia runs away. The other two join her, and they take off to the North, where Lilia believes she was born. They meet a kind lord who loans them a sword to get through an enchanted wood, but it's not enough to save Kai from being enraptured by the Elf-Lord's daughter. Lilia makes a bargain with the Elf-Lord that she will get the clasp of Odin, which is in the castle of Dalir, for his daughter, in exchange for Kai and all of the changling children he has stolen. The girls get work as maids in the castle, where the king and queen are holding a competition to find a bride for Prince Tycho. Loosely based on Andersen's The Princess and the Pea, this retelling adds a few interesting twists.
Strengths: Have to admit that the cover, like The Thirteenth Princess, was what caused me to pick this up, even though I wasn't wild to read the story. I did get drawn in, though, and really enjoyed it. It would be very good for a fairy tale unit, although I'm never sure how teachers handle Andersen's stories.
Weaknesses: The beginning needed a bit more oomph, somehow, although with this cover, I doubt that many boys will pick this up and demand explosions!
Also read a young adult book that was so packed with descriptions of a girl dying her hair and wearing weird clothing that I just couldn't get through it. It was like Vampire Kisses but without the vaguely interesting vampire parts. I can't think of anything redeeming, so I won't mention it by name. Any book with very specific fashion description can become dated so quickly.