There are no Kilroe's in the 1851 census of Wakefield or Low Townships, Ottawa county, Quebec. There is one family in Wakefield in the 1861 census, spelled "Killrow" or something like that.
This family is in the 1861 Canada census (under the name "Killrae").
This family is in the 1871 census (under the name "Rillsoe"). These are the birth dates: John and Bridget, 1832; Thomas 1858; Elizabeth 1860; Catherine 1862; Mary Ann 1864; Ellen 1868. Tim Ahles has John Kilroe's birth year as 1829.
MikeWhittiker1951 in his tree on line shared this from a stone in Farrellton, Gatineau, Canada, though he wrote a couple of the dates incorrectly and they are corrected here):
In Loving Memory of John Kilroy, Died Feb 28 1882 AE 52 yrs His Wife Bridget Tracy, Died Jan 12 1901 AE 75 Yrs Their Son Thomas Died Apr 5 1904 AE 49 Yrs Their Daughter Ellen Bridget, Died Sep 4 1878 AE 6 Yrs