The daughters' war - Christopher Buehlman

The goblins have killed all of our horses and most of our men.
They have enslaved our cities, burned our fields, and still they wage war.
Now, our daughters take up arms.

Galva - Galvicha to her three brothers, two of whom the goblins will kill - has defied her family's wishes and joined the army's untested new unit, the Raven Knights. They march toward a once-beautiful city overrun by the goblin horde, accompanied by scores of giant war corvids. Made with the darkest magics, these fearsome black birds may hold the key to stopping the goblins in their war to make cattle of mankind.

The road to victory is bloody, and goblins are clever and merciless. The Raven Knights can take nothing for granted - not the bonds of family, nor the wisdom of their leaders, nor their own safety against the dangerous war birds at their side.

But some hopes are worth any risk.

A fraught, shattering fantasy adventure, this standalone novel is set during the war-torn, goblin-infested years just before The Blacktongue Thief.