I'm not sure what the 1881 occupation actually says for father Joseph - it might be 'cannot work' - he is blind.
Silvya's age is a little out in 1881 too - she was born ca. 1845 - will post previous census details for her later.
As for Joseph, senior, he apparently wasn't too sure about his age either ...
1891RG12/2700 44 4
Nottingham St Mary
13 Risles Place Barker GateJoseph Brentnall, head, 59, Beggar, b. Notts Carlton - Blind
Sylvia, wife, 48, b. do.
Annie, dau, 16, Box Maker, b. Nottingham
Samuel, son, 13, scholar, b. do.
Emily, dau, 11, scholar, b. do.
Henry Harrison, boarder, s, 25, Printer, b. Notts Bingham
1901RG13/3169 35 23
Nottingham St Mary
13 Risles PlaceSylvia Brentnall, head, wid, 60, Charwoman, b. Notts Carlton
Emily, dau, s, 22, Cardboard Box Maker, b. Nottingham
Henry Harrison, boarder, s, 34, Printer (Compositor), b. Notts Bingham