SOLVED. Children's Fantasy: Middle grade fantasy with switching perspectives, maybe four or five. One perspective was girl, the second was her best guy friend. Set in medieval times maybe, there were mentions of princes and princesses.

[Kaitlin]

Spoilers ahead: Read in either 2011 or 2012, felt at least five years old from the wear of the book. Middle grade fantasy with switching perspectives, maybe four or five. One perspective was girl, the second was her best guy friend. Set in medieval times maybe, there were mentions of princes and princesses. The girl saved the boy in the end from an assassination attempt. The girl was possibly a red head, but there was definitely at least one character with red hair.

[Kaitlin]

I just remembered there was an emerald or gemstone of locket on the cover.

[Kaitlin]

I found it by chance when book shopping.
It's Bella at Midnight by Diane Stanley.