She gives a soft mrrrp at the question. She can't exactly answer him in speech, and he's not giving her the 'tap twice for yes' option, so she's not too fussed about it. She's pretty sure he thinks she's a normal cat anyway, so he's probably not too fussed about it either.

To be fair to his previous not-cat, she's also something else taking the form of a cat, but she doesn't exactly have a way to explain that. She sees that frown, considers her options, and abruptly rolls over, exposing a very soft belly and flexing her paws in the air. Look, she's adorable! Forget about the other not-cat who's making you sad and pet her instead!