The False Princess by Eilis O'Neal

Nalia spends the first 16 years of her life thinking she is the princess and heir to the throne of Thorvald, only to be told that she was only a decoy, switched at birth with the real princess to try to avoid a prophecy made during the queen's pregnancy that the princess would be murdered horribly before her 16th birthday.  The king and queen, having averted their real daughter's death, send the false princess, named Sinda at birth, unceremoniously away from the castle to live in a small village with her only living relative, an aunt who is less than delighted to have a fully grown niece with no domestic skills sprung on her with no means of support.
This could have had the makings of a somewhat trite and predictable story, with a spoiled girl learning humility, but the author took an entirely different path - Sinda had been a quiet, gentle, nice and scholarly princess, and she tries to adjust to the changes in her life dutifully, although without much luck.  Her aunt sees Sinda as a reminder of her dead brother, Sinda's father, and the wife who abandoned them all - she isn't cruel to Sinda, but she isn't particularly welcoming or happy to find her niece alive.  The villagers aren't entirely sure how to deal with Sinda, and Sinda's shyness and lack of confidence create a barrier between them.  The one villager who takes an interest in her is the town playboy, but Sinda misses her best friend, a young nobleman named Kieran, so much that she readily accepts the overtures.


And the surprises don't stop there - part of the spell that ensured everyone thought Sinda was the princess, Nalia, also bottled up Sinda's own natural magic, which is now twisting and turning and trying to get out, causing problems in Sinda's attempts at adjusting to life outside the castle.  In addition there are twists and turns with the secrets behind the princess switch, betrayals at high levels of government, regicide, revenge and romance.  A satisfying read with a bit of adventure and magic, some intrigue and political wrangling, touches of romance and some decent character development for Sinda, making her seem realistic but not helpless in her struggle to figure out who she really is.  There was not as much development as I would have liked for Kieran and one or two other characters - but to do that, the story would have had to have introduced some characters a lot earlier, which wouldn't have worked plot-wise.

PW review ages 10 and up.