Hi Kerri,
I have done a lot of research on Peter Dempsey b 1858 married to Mary Doyle and subsequently to Mary Mc Creary and recorded 7 children.  Living in Wexford.  I have updated all the information I found into FamilySearch.Org.
Their eldest son was Peter Dempsey (1882-1955)
married in  1901 to Maud Shiggins (b 1886) in Wexford
children
Peter (b 1902) married in Aug 1922 to Rebecca Rossiter (1901-1956)
Annie (1903-1940)
Aidan  (1911-1941)