This book is on pre-order until release date of December 30 and book delivery arrives. 
 
Everlight (Eclipse #3) by Lindsay French:
 
A new Prophet threatens all Max has built as old enemies resurface, shattering a fragile peace, in the final installment of this SF romantasy series.

Max and her partner, Nash, have built a thriving kingdom in the Valley where Max first defeated the Prophet nine years ago. She knows peace in the Skia Hellig Peninsula is never permanent, but she’s determined to secure a prosperous future for her people and her family, including her four-month-old son, Finn, and Nash’s thirteen-year-old daughter, Elsie.

It’s been eight years since a mysterious stranger promised Max’s death if she defied the natural order of the gods, and she’s no closer to knowing how to defeat him or the overlords he serves. Meanwhile, neighboring Prophet Theus of the Flatlands continues to foment rumblings of war, and Max is haunted by nightmares of the tyranny of Eskel the Ruthless and her death at the hands of Dr. Henderson.

Then, at a diplomatic summit, a foreign Prophet named Malach arrives, threatening to destroy Max and every kingdom on the peninsula. With foes on every side, Skia Hellig must unite to defeat its greatest threat yet—but its kingdoms seem perfectly content to let Max fight the deadly war herself. As if all that weren’t enough, the cult that once allied with Theus is still about, and its connection to Dr. Henderson may not be as dead as it seemed . . .