But I can't find the Harvey family either in the 1891 census
The HARVEY family (indexed as HAWEY) are also living at
72 Palmerston Road in 1891, in the same house as the child 'Ernest T. Ross' (see reply #3 above), but as a separate household.
1891 censusRG12/606 folio 86 page 62
72 Palmerston Road, Wimbledon
Charles Harvey, head, married, 26, Plumber, born Surrey Croydon
Ada Harvey, wife, married, 24, born Herts Elstree
Charles Harvey, son, 3 months, born Middlesex Hanworth