Robert Harley and Mary Downie married in Tillicoultry, Clackmananshire on 28 Nov 1765, but they seem to have moved around quite a bit as is ssen by the places of birth of their childrem:-
Marycrs. 26 Oct 1766, Tillicoultry, Clackmanshire Christiancrs. 10 July 1768, Carriden, West Lothian Helencrs. 7 dec 1770, Carriden, West Lothian Jamescrs. 29 June 1779, Torryburn, Fife Janetcrs. 3 April 1782, Torryburn, Fife Davidcrs. 16 Oct 1785, Torryburn, Fife
Sorry, I haven't found a Margaret, but that doesn't mean there wasn't one, as there is a large gap betwwen the birth of Helen in 1770 and James in 1779.