The Decoy Princess — Dawn Cook

Princess Contessa of Costenopolie knows everything a royal should about diplomacy, self-defense, politics... and shopping. She ought to. She had every reason to believe that she was groomed to rule. But her next lesson is in betrayal...

The sudden arrival of her betrothed, a prince from the kingdom of Misdev, has forced Tess's parents to come clean: She's no princess. Their real daughter was raised in a nunnery for fear of assassins. Tess is nothing but a beggar's child bought off the streets as an infant and reared as a decoy.

So what's a royal highness to do when she discovers she's a royal target? Ditch the Misdev soldiers occupying the palace, use magical abilities she didn't even know she had, restore the real princess to the throne, and save her own neck. But first, Tess has to deal with the scoundrel who's urging her to run away from it all, and the Misdev captain who's determined to thwart her plans...