I note the marriage in Londonderry, John Police Sergeant. Hugh Conway was one of the witnesses. Children you mention below. Have you found any census returns?
MCCONNELL, KING ALEXANDER BIRNEY
CONWAY
GRO Reference: 1875 S Quarter in KNARESBROUGH Volume 09A Page 101
MCCONNELL, MARGARET FRANCES
CONWAY
GRO Reference: 1877 J Quarter in KNARESBROUGH Volume 09A Page 99
Colin