Hi Bushy
This is Charlotte on the 1861 census. Looks like they got John's age wrong on 1851 and he is brother to Phebe and chearlotte his wife.
HALL, John Head Married M 48 1813 Agricultural Labourer Old Hurst Huntingdonshire
HALL, Charlotte Wife Married F 38 1823 Wood Hurst Huntingdonshire
HALL, William Son M 10 1851 Old Hurst Huntingdonshire
RG number: RG09
Piece: 976
Folio: 18
Page: 6
Registration District: St Ives
Sub District: 1 Warboys
Enumeration District: 2
Civil Parish: Old Hurst Municipal Borough:
Address: Stag And Hounds, Old Hurst
County: Huntingdonshire
dave