the two census returns for reference :
Kilroy household, Sandyhill townland - 1901
Kilroy household, Sandyhill townland - 1911
Michael snr is a farmer, and all the family are listed as born Co. Sligo. On the 1911 return they state they had 9 children and all are still alive at the time, and are married about 35 years - so c1876.
There's a good possible match for their marriage in the registration district for hat area, i.e. Tobercurry/Tubbercurry as follows :
Name: Michael Kilroy
Record Type : Marriage
Registration Year : 1876
Registration district: Tobercurry
Volume: 4 / Page : 579
A Bridget Lundy appears with the same index references to a possible cross-match. You can order research cert from the GRO using these references. These cost € 4 and will give you further details on the marriage such as date, location, places of residence for bride and groom, their father's names and occupations... reply here if you require notes on ordering these.