The Ninth Rain (The Winnowing Flame Trilogy #1) by Jen Williams

The Eborans always kept the humans safe from Jure'lia, a mysterious group of creatures, for thousands of years, until the tree that gives them life dies. Now, Eborans are dying out and threats arise from remaining Jure'lia artifacts. Vintage, an explorer, hires Tormalin, one of the last Eborans, to be her bodyguard on her quest to understand their foe.

A Deal with the Elf King (Married to Magic #1) by Elise Kova

Every 100 years, the Elf King comes to Luella's village to pick a human bride in order to fulfill a centuries old pact. The Human Queen must have magic, so Luella knows it isn't her, until a long kept secret is revealed. Suddenly, she whisked away to a new land and role that she had no preparation for and is married to the cold Elf King.