The image of Emma filled Katherine's mind. Her smiling face and genuine personality were what made them become friends fast. If Emma were happy, she would definitely be all smiles, and if she were mad at you, she wouldn't be afraid to yell at you—no matter who you are or what your status is.
The thought of Emma with a different identity was quite surprising for Katherine. It wasn't because she didn't believe people can have different identities—heck, she lived a considerable part of her life with different identities. It was just that, Emma was one of the very few people she believed to be innocent or real.
So if she wasn't really Emma Chang, then was it really possible for her to be Chris's sister? This was insane.
Katherine's eyes darted back to Chris, and her mind tried to fit the two together in one frame, but Chris's sudden announcement interrupted her imagination.