Not a sequel, and not a pre-quel as such, but you might recognize the protagonist. Characters of mine have a way of migrating from one book to another, and bits of story, not precisely matching up, do seem to fit together, sort-of. So somewhere in the future may be a book set in Poughkeepsie, where...let's call the character Molly...has not been thrown into the loony bin, and has never yet met anyone with cat whiskers. BUT....maybe that book will take place 40 years in the past, or in the future, so it couldn't be a quel of any sort. At the same time, I'm thinking about a book wherein someone with cat whiskers, who's been traveling in space with her doppelganger, comes back. If any of this confuses you, you should try being me.