If I'm right on the family (and I agree you must buy the marriage certificate to confirm the name of Martha's father) the Clarke girls seem to be dispersed by 1851.
Frances (17) and Helen (16) Clarke, both born Liverpool, are pupils at Brookfield Lodge School, Highgate Rise, Kentish Town in 1851: HO107/1498/304/69.
A Martha Clarke, 21 b Liverpool, is in Milton St, Broughton as "cousin" of Sarah Reaves, a 58 yr old unmarried Proprietor of Houses & Lane b Coventry. Also in the household is a 9 yr old Elizabeth Clarke, "cousin", b Manchester - possibly a much younger sister of Martha? HO107/2222/178/40.
Anna
