What is Blanca Mestre Agüero's importance in the novel, The Aguero Sisters?

Murdered in the opening pages of the novel, Blanca is a compelling but enigmatic character, one who's seen almost exclusively through the memories of her daughters and her husband. She's important because it is her face that Constancia later assumes in one of the novel's strange touches, and it is the memory of her nurturing (she breast-fed Reina until her younger daughter was five years old) that haunts Reina throughout her life.