Heir of the Autumn Queen (Autumn Queen Trilogy #1) by Savannah Stoltz:
 
In the heart of the mystical Staghorn Forest, a secluded village bound by ancient magic, nineteen-year-old Aurelia's life is governed by peaceful routines—until an innocent visit to the village seer on her twentieth birthday shatters her world. Embarking on a perilous journey across the four kingdoms of Iaselion and fleeing from her estranged aunt's dark ambitions, Aurelia's quest for justice leads her into a whirlwind of political intrigue, mythical creatures, and unexpected love. As she grapples with her destiauny, she transforms from a sheltered girl into a powerful leader, determined to forge her own path.

Experience a world of magic, romance, and self-discovery, where one young woman's journey to embrace her true purpose could change the fate of her world forever.