Hi Deevla,
It looks as though we have some common interest in relation to Rosanna Taaffe (nee Kavanagh). My interest stems from my mother who is a grand-daughter of John Taaffe and Rosanna. John and Rosanna's first child, Patrick Christopher (born 26-12-1894) was her father.
What I have "discovered" so far ...
John and Rosanna were married on 7th October 1894, in ST. MARY's, PRO CATHEDRAL church.
Parents on John's side were... Patrick Taaffe and Anne Taaffe (nee Graham)
Parents on Rosanna's side were... James Kavanagh and Ellen Kavanagh (nee

??)
Children... having reference to 1901 and 1911 published census records.... 7 children (2 surviving)
Patrick Christopher (b: 26-12-1894)
Elizabeth (b: 01-07-1896) see note later.
Mary (b: 18-05-1897)
John (b: 08-03-1899)
Peter (b: ??-??-1901)
James (b: ??-??-1903)
A.N. Other (b: ??-??-?

)
Note on Elizabeth... while the 1901 census return shows "Lizzie" as a family member of John and Rose, her birth cert shows her parents as Peter Taaffe and Bridget O'Neill.
I have some further info re Peter and Bridget... here's hoping you might have some further info yourself.
Regards