Hi
I have seen her on the 1851 Census in Wakefield aged 25 which makes her dob c1826.
You have omitted a very important fact - the 1851 shows her born in London - she was only visiting Wakefield. It does not show what part of London
The IGI has a couple of London possibles -
www.familysearch.org but you really need to buy a copy of her marriage cert to establish her fathers name and occupation which will help narrow down the search
MARY ANN CARDWELL Birth: 25 SEP 1825
Christening: 22 JAN 1826 Saint Mary, Newington Father: JOHN CARDWELL Mother: MARY ANN
MARY ANN CARDWELL Birth: 06 FEB 1826
Christening: 10 FEB 1826 Saint Peter Pauls Wharf, London,
Father: WILLIAM CARDWELL Mother: ELIZABETH
MARY ANN CARDWELL Christening: 12 JAN 1828 St Sepulchre, London Father: GEORGE PETTINGER CARDWELL Mother: ANN