This looks like the Robert and Sophia that married in 1829. Birth according to this in c 1812.

1851
Name: Robert Nelson
Age: 40
Estimated birth year: abt 1811
Relation: Head
Spouse's Name: Sophia Nelson **
Gender: Male
Where born: Swaffham, Norfolk, England
Civil Parish: Swaffham
Phillimore Ecclesiastical Parish Maps:
View related Ecclesiastical Parish
Town: Swaffham
County/Island: Norfolk
Country: England
Street address: North Pool
Occupation: Butcher

Robert Nelson 40
Sophia Nelson 39 hard to read where born but looks like (Nieton 51 Noeton 61 census), [Necton, Norfolk, England]
William Nelson 21 occ bricklayer
George Nelson 13 occ errand boy
Sophia Nelson 11
Walter Nelson 5
Charlotte Nelson 3
Alfred Nelson 2
Mary Ann Nelson 1 Mo


Sophia Dickerson 4 July 1781 in Swaffham Norfolk would have been 48 if she married in 1829

I think this is the Sophia ** above:

England Births and Christenings
Name Sophia Dickason
Gender Female
Christening Date 08 Jan 1812
Christening Place Necton, Norfolk, England
Father's Name William Dickason
Mother's Name Anne Dickason

I found this but cannot find record on parish records. Note spelling of surname which is also used on christening of Sophia. Update found record in parish records.


William Dickason married Anne Bennet
6 November 1811
Necton,Norfolk,England

This might be the William above

Baptism
Name: William Dickason
Gender: Male
Baptism Date: 10 May 1778
Baptism Place: Necton, Norfolk, England
Father: George Dickason
Mother: Mary Dickason
FHL Film Number: 1471680
Reference ID: Item 16, pg 60


With a lot of careful searching you might find lots of info in Norfolk for the the Dickason /Dickerson Family on this free site. This will include Sophia's siblings:

familysearch.org/search

Come back if you need more help