Hi Jack,
The marriage record is on rootsireland.ie/
Date of Marriage:13-Feb-1877
Parish / District:BORRISOLEIGH
County:Co. Tipperary
Husband William Davern Address Hollyford Occupation:CARPENTER Widower
Wife MaryRyanAddress:Hollyford NATIONAL TEACHER Spinster
Denomination:Civil Parish
Husband's Father JeremiahDavern Occupation:CARPENTER
Wife's Father EdmondRyan NATIONAL TEACHER
rootsireland.ie/ has 8 birth & baptism records for children of William Davern & Mary Ryan but they are from a few different parishes so I suspect there may have been two couples of these names - especially as there are two Johns born in the same period.(John born June 1883 & John Joseph born July 1883.
Edmund 1877 William 1879 James 1880 & Mary 1886 are from Kilcommon but different addresses while William 1881, Martin 1884 & Michael 1887 are from Hollyford, Kilcommon.
Do you have a list of the children who stayed in Ireland that you're looking for?
Having said that, the main source available for the period you're after - 1884 onwards is the irish Census. It is freely available online and 1901 & 1911 are there (no 1891). There are 98 Daverns in Tipperary in the 1901.
If you know the nmes of the children who stayed you can try the censuses & I can look for death records on rootsireland. If not I'll post the 8 records of birth/baptisms and we'll go from there.
Col