On 18 October 1814 he married Charlotte in Abingdon.
Where did you get this info from?
I can't see a marriage in any of the Abingdon parishes nor on F/Search
The 18th October date is the marriage of George to Ann Clempson - but in 1847.
There are numerous on-line trees with this family, but I can only see a year (1814) given for George and Charlotte's marriage. This could be a guess based on the baptism date of their first (known) child and George's age he would be abt 20 -21 at marriage assuming the baptism in Wotton Underwood is his and he was baptised fairly soon after birth.
The most likely burial for Charlotte is 20 Dec 1846 (age 54). On line trees have Charlotte's date of death as 17 Dec 1846 - so likely someone has a copy of the actual death certificate.
Transcriptions of the 1841 census says she and George were both born in Berkshire - although it is so faint, I'm surprised anyone can read it. There are two images for the family in 1841. One has been crossed through and a note about transfer to St Helen's parish (I think that's the reason - handwriting difficult to read). The copy version in the correct enumerator's book, doesn't have Y or N in place of birth column. The enumerator has given up recording it halfway down the page.
Given that George was actually born in Buckinghamshire not Berkshire, I don't know if we can be certain that Charlotte was born in Berkshire.
