Hi Stacie,
Do you know much about their emigration? Dates, the reason why they left, etc.? Generally more information was given at the port of arrival rather than the port of departure. If you knew which city they arrived at (e.g. Liverpool), this could be a good place to find more information.
Remember to post as much information as you can regarding 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.
Have you tried checking the land records called the Tithe Applotment Books (1823-38) or the later Griffith's Valuation (1848-64) for any of Catherin's relatives? The Tithe Applotment Books (1823-38): Microfilm copies of the books for all of Ireland are available at the National Archives of Ireland (NAI) http://www.nationalarchives.ie/genealogy1/genealogy-records/tithe-applotment-books-and-the-primary-griffith-valuation/ or the Church of Latter Day Saints (LDS). Griffith's is freely available here: www.askaboutireland.com or here: www.failteromhat.com Failte Romhat has lots of other useful links you could try looking at.
For some further assistance you might try contacting one of the following:
Cork City Ancestral Project,
c/o County Library,
Farranlea Road,
Cork City.
Tel: +353 (0)21 4346435
Email: corkancestry@ireland.com
Mallow Heritage Centre,
27-28 Bank Place,
Mallow,
County Cork.
Tel: +353 (0)22 50302
Fax: +353 (0)22 20276
Email: mallowhc@eircom.net
Website: http://mallowheritagecentre.com
Cavan Genealogy,
1st floor,
Johnston Central Library,
Farnham Street,
Cavan Town,
County Cavan.
Tel: +353 (0)49 4361094
Fax: +353 (0)49 4331494
Email: cavangenealogy@eircom.net
Please make sure you link anyone else in your family who is interested in their Irish heritage to our site - and indeed anyone else you know of Irish heritage.
Kind regards,
Genealogy Support
Ireland Reaching Out