Is this John Roberts' mother + siblings in 1901 (no sign of John)
1901 Census (ref. RG13 5287 39 9)
Address Pistyll Du, No 3
Jane Roberts, Head, Widow, 61, born Cerrig y Drudion
James Roberts, Son, Single, 25, Agricultural labourer, born Caerhun
Jane Roberts, Dau, Single, 25, Dressmaker, born Caerhun
Chasing surname Roberts in N. Wales is a daunting task - especially when John appears to have married a Roberts!