Have you reached Colin McGaffin with these Knocknamuckley families? If not, write me at rconard@blarg.net Jane Gibson seems to be a second wife and I don't know the first. Denis would probably be named after Elizabeth Dynes, his grandmother and wife of John. Dynes is on the birth record, but Denis is a common substitution. Don't have the 1881 birth but here is the 1857 census
john gaffikin 34 weaver
elizabeth gaffikin 34
mary jane gaffikin 10
nicholas gaffikin 7
thomas gaffikin 5
john gaffikin 3
margaret ann gaffikin inf
thomas gaffikin 32 weaver
catherine gaffikin 70 mother
anne gaffikin 22 weaver sister

thomas gaffikin 39 weaver
elizabeth gaffikin 26
james gaffikin 6
Sarah gaffikin 3