I think that maybe Winifred's mother died?
In 1891 and 1901 census returns, Winifred is with her grandfather and his new wife:
1891, reference RG12, Piece 2062, Folio 86, Page 20
36 Harold Street, Hereford
Criddeford, John Head M 52 Cabinet Maker b Totnes, Devon
Criddeford, Susan Wife F 45 b Montgomeryshire
Roberts, Winifred Granddaughter F 6 b Oswestry
1901, reference RG13, 2481, 79, 11
38 Harold Street, Hereford
Criddeford, John Head M 62 Cabinet Maker b Totnes
Criddeford, Susan Wife F 55 b Llanfair, Montgomeryshire
Roberts, Winnefred Granddaughter F 16 b Oswestry
In 1881, John Creddeford is a widower.