It seemed Nissa was wrong about her assumption, for the poor girl seemed honestly confused by her question. A real witch would have proudly proclaimed of whose bloodline she was of...and then sneered at her for being a vampire and making her skin crawl, as was the normal witch reaction to being so close to one of Nissa's kind. This girl didn't seem to be physically affected in any way -- another sign that Nissa was way off. But, then, why didn't her reflection match her face? It couldn't be the mirror, for Nissa's face was reflected back the way it was supposed to, as were the others who were near the mirror. It didn't make any sense.
"No, I didn't mean that," Nissa said, "but forget that. Sorry to be blunt, but I'm curious. Your reflection, it's...off."