Thank you for those details, BumbleB, I do not have that marriage certificate.
Here is Sarah Ann Porter in 1851:
1851 English Census, 6 Regent Place, Tower Hamlets, London
Robt. Storks Porter, Head, U., 37, House and Estate Agent, Highgate, Middlesex
Mary Ann Porter, sister, U., 42, Finchley, Middlesex
Elizabeth Porter, sister, U., 39, Highgate, Middlesex
Maria Porter, sister, U., 25, Stepney, Middlesex
George Henry Porter, brother, U., 22, Nautical Instrument Maker, Stepney, Middlesex
Sarah Ann Porter, niece, 3, St Georges East, Middlesex
Henry Robert Porter, nephew, 1, Bethnal Green, Middlesex.
Notes: Sarah Ann and her baby brother Henry are in the household of her mother's siblings.
I haven't been able to find any of this Porter family in the 1861 English or Scottish Census. Would they have gone to Ireland?
John