Thank you goldie61 and sancti for your input and look ups.
So. thanks for that.. on the 1861 Census = it shows that Elizabeth is 3 years older than Willam..somehow it seems in those cases, the woman will decrease her age as to be younger than the man. If she is born 1826ish that would make her 20 at the 1846 Dec 13th Marriage..I believe that they were Protestant. My granny's age was always a few years earlier than granddad's so he always appeared "older" than her..So I wonder if Elizabeth Houston Duff did that. I do know that some people really are unaware of a persons age. It just isnt of any importance to them. Of course, to those of us searching, it can make a big difference in time and possibly money, when it is necessary to look thru a lot of data.As an aside I know that one of my inlaw's mother married at 14 and that was in Canada 1915 ish...
I noticed that the same address 95 Candleriggs in 1881 became Blythswood District and prior was Central District. When looking at BMD's and with a sometimes great variety of names to choose from; I often "opt" to stay in the same district and then not knowing its changed names...of the districts. Of course, sometimes I'm wrong.