With the 1851 & !861 Censuses and the Drake Family Tree on Ancestry in mind I had a rummage around in Ancestry PRs for the birth or baptism for Charlotte Webb.
The Censuses and the Drake tree would see Charlotte baptised in 1796.
1851 Charlotte born in London.
1861 Charlotte born in Hillingdon Middlesex.
Drake Family tree, Charlotte born 14 May 1796 and baptised 3 Jul 1706 at St Pancras Old Church, Camden, the daughter of James and Sarah Webb.
The Drake tree is correct in everything when compared to the PR entry except the mother's name is Ann.
There is a Charlotte born 2 Aug 1795 and baptised 23 Aug 1795 at St Mary Magdalene, Old fish Street, City of London, the daughter of James and Sarah Webb. Not a bad match for the 1851 Census I suppose.
Also there is Charlotte baptised 14 Mar 1794 (born 25 days before) at St Dunstan and All Saints, Stepney, Tower Hamlets, Middlesex, the daughter of James and Ann.
Although the 1861 Census gives Charlotte's birth place as Hillingdon, she was consistent in both Censuses as being born about 1796, the City of London Charlotte is closest to the year 1796.
I would be very grateful for the opinions of others on the matter.