1871 census RG10 198 folio 37
10 Kilburn Priory Hampstead St John London
Elizabeth Chant 40 Sherborne, Dorset, Domestic Servant Married
Robert W Chant 15 St Andrews, Middlesex, Servant at a chemist
Though Elizabeth is indicating she is married there is a possibility she was a widow by 1871, or perhaps her marriage had 'broken up'. If Robert senior was around, as a 'singleton' he would be harder to find.
Regards
Valda