Hi Donna,
Thank you very much for your message.
Fortunately, Catholic records in Tallow start as early as 1797 so hopefully you may be able to find birth/marriage records for the couple is they were indeed from the parish.
http://www.irishtimes.com/ancestor/fuses/rcparishmaps/index.cfm?fuseaction=showidrecords&CityCounty=Waterford&parish=Tallow&churchid=1120
Most Catholic records are still held locally so it may be a good idea to contact the local parish priest for some possible assistance. Here are the contact details:
http://www.waterfordlismore.com/parish-details/?parishID=45
Alternatively, as you can see from the Irish Times link above, Waterford Heritage and Genealogy Centre have some copies available. Here is their email if you would like to contact them:mnoc@iol.ie
Some other websites that you may find 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
Irish Genealogy Tool kit: http://www.irish-genealogy-toolkit.com/
Genealogy links: http://www.genealogylinks.net/uk/ireland/waterford/index.html
From Ireland: www.from-ireland.net
Waterford Library: http://www.waterfordcity.ie/library/iguana/www.main.cls?p=bc1d4f27-9c52-4d61-94cc-f197673e7ad4&v=96512350-cb7e-4884-830b-9bbc0be46682
Kind regards,
Genealogy Support