Here is the 1881 census of Edward Killey/Catherine Cubbon
1881 Castletown
, C4, 17, 91, KILLEY, Edward, Douglas Street, Head, Married, 23, Mariner, Michael
, C4, 17, 91, KILLEY, Catherine, Douglas Street, Wife, Married, 26, , Malew
, C4, 17, 91, KILLEY, John Edward, Douglas Street, Son, , 2, , C.Town
, C4, 18, 91, KILLEY, Katie Jane, Douglas Street, Daughter, , 5/12, , C.Town

I couldn't find anything at all on Ruth Lucy either--are you sure she is from Isle of Man?

Donna