Dear Liz
Welcome to Ireland Reaching Out and thanks for your query.
The best thing to do is to search www.familysearch.org or www.rootsireland.ie for a baptism record for Catherine. By gathering as much information as you can, you will be able to ascertain whether the McClafferty?s in Ballyconnell are your ancestors, though it seems likely, given that the forge is mentioned. As you can see from the link below, Raymunterdony is a Civil Parish in Donegal: http://www.irishtimes.com/ancestor/fuses/townlands/index.cfm?fuseaction=TownlandsInCivil&civilparishid=789&civilparish=Raymunterdoney&citycounty=Donegal
Best of luck with your search
Clare Doyle
Genealogy Support