A Promise so Bold and Broken (Compelling Fates Saga #2) by Sophia St Germain:
 
After saving her rebel friends on the final day of the election, Elessia is on the run.

But the danger is far from over.

As she fights her guilt for betraying Loche, the man she foolishly believed could mend her broken soul, and wrestles with the unexpected emotions stirring within her for Merrick, her fiercely loyal guard, Elessia learns of the rebel’s true plans—plans that threaten every loved one she’s left behind.

But it’s the even greater peril looming on the horizon—the one that could shatter the very foundations of their world—that forces her to decide whether she is willing to embrace her birthright to the Rantzier name and, with the help of Merrick and his band of unwilling warriors, lead the journey to unite the warring factions of Havlands before it’s too late…

Or before the Fae king and human regent find her.