Whitear not a common name in Devon, there are some in Hampshire I think. Might be worth looking at John Duckham and see if he has military connections. Another thing to do is look at births of a George, no surname on line on find my past, for 1791, and the list will give a blank in the space for fathers name. I found 3, Mortimore at Sandford, Shaddick at Bideford and White at Ipplepen.
Also look for deaths of a Whitear around 1790-1791 in case she was a widow.
A bit complicated I know, but all avenues should be checked out. Hope this helps.