Thank you for your message.
Have you tried looking for information in Church records?
Most Catholic records are held locally. The Irishtimes website however, does give an overview of what records are available in specific parishes. To see what is avalable in St. Catherine's follow this link:
For Church of Ireland records check:
You could also do a search for Felix in Griffith's Valuation. This was a property valuation survey carried out in Ireland between 1848-1864. You can search it online here:
Did either of them emigrate? If so, do you know much about their emigration? Generally more information was given at the port of arrival rather than that of departure so emigration records can sometimes be a valuable source of information.
If they remained in Ireland you could so a search for them in the 1901/1911 census records here: http://www.census.nationalarchives.ie/search/
Some other websites which may be useful are:
The National Archives of Ireland http://www.nationalarchives.ie/genealogy1/genealogy-records/introduction/
The National Library of Ireland http://www.nli.ie/en/family-history-introduction.aspx
Family Search: https://familysearch.org/
Genealogy Links: http://www.genealogylinks.net/uk/ireland/dublin/index.html
Dublin Heritage: http://www.dublinheritage.ie/
I hope that this helps. Remember to post as much information as you can with regard to the people you are researching. The more information you post, the more likely it is that one of our volunteers will be able to advise or assist you. Also include information concerning which sources you may have already used so others may further your search.