If his father was Peter rather than Michael there are births to Peter KELLY and Jane DOLAN/DOOLAN in Kilcock that could be his family
Daniel bap. Feb 08 1880
Michael bap. Nov 27 1881
Thomas bap. Dec 06 1884 d. possibly 1885 looking at civil records
Bridget Ann bap. Dec 16 1885
John bap. Jun 02 1888
Possibility for Peter and son John on 1901 census -
LINKJane possibly died in 1891 -
LINKAlso if reference to his father dying just before the murder is correct
Civil Death Record Peter KELLY Celbridge 1915 Q3 V2 P275 -
LINKFollowing up on the children with such common names could be difficult if they moved tp foster parents or an orphanage
One approach could be to hope if they married that their baptism records would show that