Neil, I've recently discovered that more of my lot went to Canada. The family of David FAIRBAIRN and Jane HERD seem to have emigrated after daughters Mary (born 1830 Ladykirk Berwickshire) and Janet (born Swinton & Simprim, Berwickshire 1832) and before sons David McDougal FAIRBAIRN. 1835, Robert c 1837, and dtr Esther supposedly 1840. Place information for these latter children is sometimes given as Cambden St Mary's Perth Ontario, and for Esther as Napanee. Eldest son of David and Jane was an Archibald, but he's Archibald James, bornc 1827. It looks like he married Jane TRACY and had a son Archibald James (not strong on originality for names). Archibald had a brother William but that was in 1842. By the 1850 census most of the family, apart from Archibald, were in Wisconson.
It is probably complete coincidence, but the Napanee caught my eye so I thought I'd mention it. Besides, someone might have info on what happened to the rest of the children I've not yet found much on (Jane, Elisa (Alice/Alison?), mary, Robert, and James)
And if your line has any males still FAIRBAIRNs who might be willing to participate in the FAIRBAIRN Surname dna project, send them along, who knows, you might break thru your brick wall. (http://www.familytreedna.com/public/fairbairn/) Regards, Lorna http://familytree.lornahen.com/spFAIRBAIRN.htmhttp://familytree.lornahen.com/spFAIRBAIRN.htm