She/her. The Stonewright is a venthyr, the Harvester of Wrath of the Court of Harvesters.
She is a former Night Warrior, and the first venthyr created from a mortal soul.
She refers to the stoneborn as her children and is referred to by General Draven as the "mother of stone" and "the mother of the stoneborn".
she was the one who created the stoneborn and formed the Stone Legion when the Maldraxxi forces did not come to defend Revendreth from the invasion of the Light.