1871 Glantaff Road, Merthyr Tydfil, Glamorganshire
William Edmonds Head 31, widower, police constable, St Athans, Glamorgan
Catherine Edmonds Sister 25 St Athans Glamorgan
Mary J (Jane) Edmonds 4 Daughter, Aberdare
As said William Daniel is with his brother David. First wife died between birth of William D and 1871, marriage and death of first wife falls between census.
Looking at the birth index on GRO suggests Mmn as Thomas. 3 possibles marriages on FreeBMD.
The first 2 children on 1881 census were not Eleanors, but by his first marriage. He remarried your ancestor 1872. The previous children are half siblings.