The Heir of Swansgrove (Swansgrove Chronicles #1) by KJ Pricthett:
 
When fourteen year old Acacia Wheatley moves from sunny California to rural Pennsylvania, she thinks the biggest of her problems will be making friends and getting acclimated to her new school. However, less than 24 hours into her high school career, she learns that she is a mage and must quickly learn to master her powers before they can cause more harm than good. 
 
For Acacia isn't just any regular mage, she's the Heir of Swansgrove, the descendant of a powerful family of mages. According to those around her, Acacia is a chosen one, the mage with the power to finally defeat the dark mage Sisyphus and his cronies, that is, if she can master her newfound powers. 
 
Trouble seems to follow Acacia wherever she goes, and as time goes by, she realizes that it may be up to her and her friends to make sure powers of darkness don't destroy her new home.