He doesn't hit her shoulder. She's too fast for that.

Instead his blade plunges thorough the side of her breast, down through her back, and in the motion of her dodge the edge slices its way out of her, leaving a cleave two inches deep under her arm. It's a fatal wound. She's not stupid. It spurts blood like a fucking hose. She rolls flat on her stomach, trying to wrench her wrist from his hand, using her weight to try and get him down in the sand.

Because she can't stand, she realizes as she grabs for his face. But that doesn't mean she can't blind him.