Wel I just found the death registry for my Samuel Adair and it ties in with your line as it identifies his parents as Samuel Adair and Jane McLellan.It also notes that he was born in Bertie Township which I believe correlates to your Samuel and Jenny who orignially settled near Fort Erie correct?
In any case working back my GG Grandfather was Samuel Adair b. 3 Oct 1868 in Kinloss Bruce Co Ontario d. abt 1932 and was married to Mary-Ann Pickell 29 Dec 1897.Their marriage registration shows Samuel's parents to be Samuel Adair and Sarah A Thompson.1901 Census shows the family of Samuel and Sarah to be located in Brooke Lambton County (Film #T-6476 Div #2 Page #6(con't on 7) Entry #49 Family #67) with Samuel b.19 Nov 1842.This closely correlates to the death registration (Enniskillin #017220) which states he was 74 years 6 months 7 days old on his death 16 May 1917 (09 Nov 1842 not including leap year calculations) and it is this document which states that he was born in Bertie Township and that his parents were Samuel Adair and Jane McLellan.
Samuel and Sarah were married 05 Aug 1868 but I haven't yet found a marriage registration or certificate but there is an IGI Individual Reference(Batch M585631 Sheet 00) for the marriage of Samuel and Sarah at the aforementioned date in Bruce Ontario Canada.The IGI confirms that Samuel Adair and Jane McLellan where the parents of Samuel Adair.
I still have much to verify but it looks likely that we are of the same line.Whatever you may have to confirm and perhaps shed light on the ancestry of Samuel and Jane would be very much appreciated