Secondhand Charm by Julie Berry (Published by Bloomsbury, October 12, 2010)
In a secluded village, magic sparkles on the edges of the forest. There, a young girl named Evie possesses unusually strong powers as a healer. A gypsy's charms—no more than trinkets when worn by others—are remarkably potent when Evie ties them around her neck. Her talents, and charms, have not escaped the notice of the shy stonemason's son. But Evie wants more than a quiet village and the boy next-door. When the prince's carriage arrives one day, and his footman has fallen ill, Evie might just get her chance after all . . .
This sounds just like the kind of fantasy novel I love to read! I don't think there's a final cover picture available yet but I saw one in a catalogue that was really pretty but I didn't post it with this because I'm not sure it's the final cover.