Try this link, it may help.Excellent site on early Fairbairns.
The links are sometimes a little tentative as there were a lot of Fairbairns in the area and a great many of their children had the same names.George F and Mary produced 6 children between 1750 and 1764. John 1750, Jean 1752, Elizabeth 1755 or 7, James 1755, Betty 1761 and George 1764.John F, appears to be the son of David who married Janet Bald.I haven't as yet worked out the parentage of George and am not sure the descendants of this line have been traced on any of the published trees. Hopefully one of the top researchers will help you out soon. Tara Hawkins or Sanna Gaffney may be able to assist.