Hi Christine,
Many thanks for the information, I like a mystery but this is taking some unravelling!!
The dates you ask for of the other children are: 1851 Census: Catherine (d) age 24, George (s) age 14, Margaret (d) age 12, Jane (granddaughter) age 3, James Thompson (father) age 90 born in Scotland and John Thompson as their Father, occupation Tailor and condition Widowed. I wonder if Jane is Catherine's daughter?
The 1841 census I have (if the correct one) states: John age 20 (1821), Robert & Catherine both age 15 (1826), William age 13 (1829), Isabella age 9 (1832), James age 8 (1833) George age 5 (1836) Margaret age 2 (1839). There are neither parents listed.
Today I found on Ancestry someone else researching John Thompson and a lot of their information confirms what you have found, with a couple of differences.
John Thompson born 1791, but in Scotland not Elsdon, his father James Thompson born Scotland 1761-1852, which makes him 90 in 1851.
Margaret Thompson born 1798 in Landshot, Elsdon, died the Folly 12.09.1844 , which is the same day and month as your findings but 5 years later.
Marriage between John and Margaret 26.08.1815.
All the same children listed as the 1841 census above, with Catherine & Robert both born 04.06.1826 at Heatherwick.
Margaret born 17.01.1839 The Folly.
Hope you can understand this!! Would you let me know how to contact Durham and ask it they have it in the Bishop's Trancripts.
Once again thanks very much for your time.
Jenny
PS Do you think John may have been married twice?