The Dawning of Power Trilogy

Catrin Volker dreams of a peaceful life training horses. It's not to be. Comets appear in the night skies, announcing the return of a goddess. While trying to save her friend from bullies, Catrin unknowingly triggers powerful, ancient, magic and fulfills a prophecy that says she will destroy entire nations.
The World of Godsland Young Adult Epic Fantasy Series includes:

The Dawning of Power trilogy
Call of the Herald
Inherited Danger
Dragon Ore
The Balance of Power trilogy
Regent
Feral
Regal
The Artifacts of Power trilogy
The Fifth Magic
Dragonhold
The Seventh Magic