I hoped you knew something about the dates of death that you mentioned in your first post, you seemed to know that not all of them survived.
The 1841 census had ages all rounded down to the nearest 4 for anybody aged over 15, so this sometimes accounts for a certain amount of discrepancies, but the difficulty here with the ages is that not being able to see the original image the fault may be in either the writing or transcribing, it's not as easy as the English ones, although they aren't always easy either
There's no easy answer to your question, unless anybody was able to check the original document, which I can only assume might be possible in a Record Office in Scotland as the English ones are available around the Counties.
One way is to try to find the alternate family in later years which I tried to do unsuccessfully. I must admit I jumped on Jessy/ie with the correct named parents and some siblings. I think your best bet is to find the birth for either Agnes or Peter, since they don't appear in the 1851 census and see what their mother's maiden name is, that should confirm it one way or the other I hope.
Just to hopefully give you a laugh, I checked for an Agnes Thomson in the 1851 census and found one, possibly with a father John, who was a prisoner in Aberdeen, occupation "Vagrant Selling Wack".
Nice one Joe, that seems to have solved it.
