Yes, in Scotland married woman sometimes reverted back to their maiden surname on the death of their husbands, but is this the case with the “Jean Paton” on 1841 census recorded under Vain?
Jean Reid, daughter of William Reid & Jean Patten/Paton, is this the Jean Reid registered as aged 45 on the 1841 census? If this age is correct she would have to be the twin sister of David Reid, this being his declared age, but his sister, Jean Reid, would have been (52 in 1841. The death of Jean Reid aged (79) in 1869 would have her born 1789/90 (correct for her birth), but is this the Jean Reid on the 1841 census aged (45)?
All Kinds of scenarios and permutations open up; is Reid her maiden name or married name? Are the two, William Reid & David Reid recorded, her two sons, and nothing to do with the offspring of David Reid & M.Barclay?
Anomalies regarding age on census records are notorious. For instance, William Reid, born of William Reid & Jean Patten/Paton, on the 1851 census records his age as (69), yet in the 1861 census it has his age as 72. His 1864 death certificate age is recorded as 84 (correct for his birth date 1781).
There are two David Reid’s recorded being born to a William Reid in “Portmoak”, (1) in 1791, declared mother Jean Paton , The other 1794, no mother declared. What is the correct age and parentage of the David Reid who married M. Barclay? It was hoped that a cross reference of age and address could have been made through a combination of the census records and death certificates to determine this. His death certificate declares (69) in 1864.
No address was recorded on either death certificate of William Reid or David Reid, other than the general Scotlandwell Portmoak.
However, examination of these two documents gives enough to establish that David Reid, who married M. Barclay, was the brother of William Reid. Son to this particular couple of William Reid and Jean Patten/Paton, the brothers died within (64) days of each other.
If the two registered David Reid births were to this particular couple (William Reid & Jean Patten/Paton) the first born in 1791 died, or recorded age on records are incorrect.
Regarding Marion/Mary/Mary Ann Barclay, Wife of David Reid, I have copy of M. Barclay’s death certificate, which I would be happy to transcribe details off, if they are not held already by those with interest in this genealogical line.