Dawn of Hope by Amanda Briar

A mythical island. A magical cure. A choice between duty and love.

Lennox Holt has spent her life preparing for her twenty-first birthday ceremony, where she will finally be recognized as the future queen of Blackwood. Her father, the king, has ignored her, keeping her hidden away from the kingdom under the guise of ‘protection’, ever since her birth caused her mother to fall into a perpetual sleep.
Isolated and alone, she’s all but given up hope of ever having a loving parent or family until she learns of a mythical island named Dawnlin that is said to hold a cure for any ailment. When her ceremony doesn’t go as planned, she takes matters into her own hands and seeks the Guardian to take her to the island so she can heal her mother.
Along the way, she meets Dane, a handsome and mysterious stranger who is seeking the same elixir. But Lennox doesn’t know the island is full of magic and secrets, including the location of the cure.
Hunted by the dangers of the land, both magical and human, Lennox must survive while searching and avoiding the clutches of the Castaways, who are trying to steal the cure for selfish reasons. After finding everything on the island she has always dreamed of — freedom, family, and love — Lennox must decide if the duty to her kingdom and the promise to her mother outweigh her new life on Dawnlin.