Hello Gail: Unfortunately my William John Davison was born in 1795 and came to Canada from Belfast,with his wife Jennie McFateridge and son John McKay Davison, born 1814.
I found John McKay Davison born 1814, married to Jane Swanzie about 1839. They had 4 sons and 1 daughter -NANCY D.
Davison, born Jan.1, 1841, and married to Bowen Alsworth
Lucas. They lived in Yarker, Ernestown/Lennox, Ontario.
Does this fit with any of your info? Maybe it is a co-incidence as the name Nancy was a popular name back then.