The Historical Atlas of the County of Wellington, Ontario has an obituary for George McKnight, that lists his wife Mary Smith and his children. George McKnight was born about 1817 according to the various census, but this biography/obituary states he was born in 1827 in Fermanagh, Ireland and he emigrated to Canada in the early fifties (1850) with his family. This is incorrect as Isabella his daughter, was born in Ontario about 1839. So while some of the information is suspect it does give a sense of who George McKnight was.
From other sources, I know he came to Wellington County by 1854 as he is listed as one of the first owners of land in Minto Township at Concession 1, lots 41 and 42. The biography states "There were no roads at this time and the McKnight found their way through Wallace and up to their location the 'blazed' path. Here Mr. McKnight made a small clearing and built a log house, eventually clearing the whole farm and living upon it until his death." The article also states that he was a Conservative and the family were members of the Church of England.
The most valuable part of the biography lists his children and more importantly who they married. Unfortunately the daughters are listed by their married names, i.e.: Mrs. Robert Newton. This takes some sorting out to discover which daughter it means. Luckily the men fare better, they are listed by name and the full name of their wives.
By using the biography as well as information from other sources here are the family marriages:
Most of the family seemed to stay in the Wellington County area and George McKnight's farm stayed in the family for years after his death. I believe there are still quite a few McKnight family descendants in the area to this day.