My GGG Grandfather was also William Guest (1776-1869) who married Elenor Ardiel(1791-1859). I came across this information just a few weeks ago in a book I just received, London Township Families, Past and Present.You had mentioned that in your information you have Elenor's siblings as Margaret, William, Lancelot and James.Where did you find this info.?
In this book under the Ardiel name it tells about the families of Leonard (1773-1843) and his younger brother John (1786-1870) emigrating from Ireland to Canada and how John and his father had been active in the British militia during the Irish Rebellion of 1796.
I had wondered if Elenor might have been their sister, but I see no mention of these names in the book.