My wife, Carole is a cousin of your father, but I am the genealogist in the family. The Mayhew's can be traced back to Pierre Maheu in the late 1600's in Quebec. After getting the marriage registration for George and Jane from Manitoba, I was finally able to identify his parents and trace the Watson's back a couple of more generations in Ontario.
Carole's parents were Clarence "Johhny" Watson and Lydia nee Kreutzer.
I am happy to share whatever is of interest to you.