Hi Betty
I also show that Martha married William Gow. I show she was born Dec 1797 at Digdeguash and died Sep 17, 1882 at Chamcook. She married William Gow, Senior on Aug 3, 1818. This came to me as part of another researcher's GedCom file, so I have no sources and you are cautioned to verify the information.
I descend through David and Mary (Steele)'s daughter Janet who married Dugald Carmichael. The GedCom indicated there were 8 children total.
Derek