My Sarah Kirby who married Theodorus Neale was a known daughter of RICHARD Kirby/Kerby. Some researchers suggest that he was a son of Enoch Kirby, but Richard's birthday appears to be ca. 1726. If Enoch Kirby really was born in 1716 (and I have no reason to think that he was not) then he couldn't have been the father of my Richard Kirby.
Also, there is a gap of many years between Richard, b. 1726, and his potential sister Elizabeth (m. Thomas Ignatius Carrico), b. 1741. Of course, there could have been other now unknown siblings between them. However, I don't think that they were siblings, based on the various birth dates.
There are strong connectives between my Kirby/Neale family and the Kirby/Carrico family (primarily in Washington County, MD, and then later in Kentucky, and therefore I do firmly believe that they are somehow related. Perhaps (please note the word "perhaps" amd the subsequent question mark) my Richard Kirby is a younger brother of Enoch?
I have attempted to research my Kirby family, with the help of a professional researcher in Maryland, and I cannot find anything firm any farther back than Richard Kirby (ca. 1726-15 Oct 1785). It isn't for lack of trying!
I can send you the names of Richard's children, if you would care to see those. Certain given names might suggest some kind of connection to you.