Maybe Alexander and Helen split up

1871 has:
Ellen Walker 58 Washerwoman b. Old Meldrum
Joseph Walker 27 Labourer (dock)
Margt Walker 23 Wool Mill Worker b. Aberdeen
Joseph A Walker 12 grandson b. Aberdeen
Address: 14 Chapel Lane, AberdeenMaybe this entry for Alexander in 1871?:
Alexander Walker 63 Labourer (road) b. Old Meldrum
Address: 13 Back Wynd, Old MeldrumMonica