Judy,
I had a search to try to find out what happened to Agnes Watson, born 1800. You might like to check the following...
I make it that she married a John Hughes on 28 May 1824 at Applegarth & Sibbalbie, and she died under the name Agnes Hughes on 13 June 1875 at 4 Old Boreland, Colvend, Kirkcudbrightshire. On the death cert image on Scot... Peo...le, she is aged 74, and her parents are listed as Isaac Watson, Ag Labourer deceased and, annoyingly, --- Watson, Deceased. So no first name name on the death cert for Agnes, her mother. Just a stroke of the pen and Watson.
However, on the census from 1851 up to 1871, Agnes Hughes is listed as having been born at Lochmaben, and as the aforementioned death cert also has her father as Isaac Watson, it is her for certain.
She married John Hughes in 1824. However, on the 1841 census at Banks of Dounstinehall, Colvend, Kirkcudbrightshire she has - what looks like - six children, but the oldest, Janet, was born in 1922. ...But the 1841 census doesn't say what relation these children are to her... so it has yet to be proved that they are all hers.
1851 at Burnbank of Achenlah, Colvend, Kirkcudbrightshire she has Helen, aged 13, Robert, aged 11, then Joseph, 9, who is listed as g/son. And then there is Elizabeth aged 9 and David aged 5, all born at Colvend. All except Joseph are listed as her sons & daughters. Husband John isn't with her on this census. I saw him elsewhere though.
1861 at Bogfoot, Colvend, Kirkudbrightshire ... John Hughes, aged 61, born Dumfries, Ag Labourer; Agnes, wife, 60, born Lochmaben; Elizabeth, dau, 18, b Colvend.
1871 at Boreland Old Mill, Colvend, Kirkcudbrightshire. ...John Hughes, 72, b Dumfries, Pauper, Ag Labourer; Agnes, wife, 71, b Lochmaben; Elizabeth, dau, 29, b Colvend. Field Worker.
So Agnes Watson, born 1800, married John Hughes in 1924 and lived at various places in Colvend until she died in 1875.