I know what you mean. It's not that she covers her face that does it for me. I cover my face, too, when I cry hard. It's that her body is quite uninvolved. Deep anguish, or shame, involves the whole body. Mouth, shoulders, guts.
Her runny nose, her tears that merely trickle from the corners of her eyes--I don't think these are signs of faked emotion necessarily, but of shallow, disconnected emotion. Except for a couple of rare instances, where she actually sobbed, her face never looks ravaged afterwards. No red blotches, no puffy eyes or lips, no raw nose. She emerges from her crying spells with her face even-toned and smooth. Even a short crying jag with leave some mark on the face.