Whispers Under Water - Elemental Guardians Series, #1

Caitriona was a warrior who protected her island village from mythological scourges. At least, she was in the fairy tales her father told her at bedtime when she was a little girl. In reality, Caitriona lives in San Francisco and passes the days being a normal teenager. She punches the clock with the odd assortment of employees her mother has collected at their bakery, Tea Cakes. She spends her free hours with her two best friends, Georgia and Wyatt.
And she ignores the secret that has followed her around like a second shadow since her mother told her The Truth on her thirteenth birthday. But time has trickled through the hourglass, graduation is over, and she can't hide from that shadow anymore. Now she must enter the mysterious world from her father's stories. A world that is her last connection to him that will distance her from the living people she cares most about. Caitriona's journey begins in this first book of the Elemental Guardians series, where magic is deeper than what the eye can see.