I'm also connected to the Kilby family of Hawling though perhaps going back a generation before your first listing. I have a Hannah Kilby b. 1775 who married a John Haynes in Feb 1793. Hannah was the daughter of Thomas (b. Jun 1745, Naunton by Stow) & Mary Kilby. As far as I can tell there were at least 4 other siblings: Thomas b. 1777 Betty b.1779 Ann b. 1790 William b. 1794
Most of my information has been gleaned from the IGI. I guess its possible the William listed is your William - I haven't done any checking on that. I've also gone back a further generation to a Richard & Esther Kilby.