Hi Jill,
Presumably, this is Frances' death record?
Name:Frances Marlborough Allen
Estimated Birth Year:abt 1814
Year of Registration:1890
Quarter of Registration:Jul-Aug-Sep
Age at Death:76
District:St Saviour Southwark
County:London, Surrey
Volume:1d
Page:95
And this is the family in 1851?
Name:Frances Allen
Age:36
Estimated Birth Year:abt 1815
Relation:Wife
Spouse's Name:William H Allen
Gender:F (Female)
Where born:Clerkenwell, Middlesex, England
Civil parish:Southwark Christ Church
County/Island:SurreyCountry:England
Registration district:
St Saviour Southwark
Sub-registration district:ChristchurchED, institution, or vessel:9
Household schedule number:18
Household Members:
William H Allen 41
Frances Allen 36
Sarah Allen 9
Jane Allen 6
I realise that Frances' year of birth differs from the 1817 that you have in both these sources.
Through process of elimination, I believe Frances' father was William Marlborough and her mother was also Frances. I've looked at London Baptisms and found these, but I can't see any more info than this-maybe someone will be able to look for you.
Name
Parent Names
Frances Marlborough
William Marlborough,
Marlborough
Frances Marlborough
William Marlborough,
Marlborough
George William Marlborough
William Marlborough,
Frances Marlborough
Isabella Marlborough
William Marlborough,
Frances Marlborough
Mrsp