Sarah Greathead formerly Brown late Taylor

I have tried hard this month to sort out my personal brickwall with my 2x great grandmother Sarah Brown I have a copy of her marriage certificate to William Greathead in 1852 where she was described as a spinster

On the birth certificate of her first son Thomas in 1853 she describes herself as Sarah Greathead formerly Brown On the birth certificate of her following sons Peter in 1855, William in 1858 and George in 1861 she describes herself as Sarah Greathead formerly Brown late Taylor
On the 1851 census Sarah can be found with her parents Peter and Isabella (née Baker) Brown and is listed as single. Had she married before this date and the family were covering up. Maybe it was a short marriage and her husband died?

I searched long and hard for a possible marriage of Sarah to a Mr Taylor. I found what may be the marriage on 18 December 1847. Sarah Brown aged 21 married James Taylor in Stanhope. Sarah's father was Peter Brown a labourer. The witnesses are not family members

I then searched for a possible death of James Taylor prior to 1851. I identified four candidates 1848/Q1 Darlington 24-36, 1849/Q3 Auckland 24-12, 1850/Q1 Auckland 24-7 or 1850/Q3 Houghton le Spring 24-115 and bought their death certificates.

None of these were the correct James Taylor. Anyone any ideas please?