Hi Jill, think that gave us a little breakthrough, I found the marriage of John Watts and Maria Shaw on the 4th June 1830 in St Catherines Parish, Dublin, you can view the transcription here, click on Church Records, area Dublin, Dublin is one of the few areas with online Church records done and transcribed and free to search, https://www.irishgenealogy.ie/en/ The witnesses are Thomas Roberts and William Shaw, it is a Church of Ireland marriage, that is Anglican or Prostestant.
What is interesting is the address is Ryevale House, Leixlip, (this is on the Dublin / Kildare border, for civil purposes it is Kildare but the church diocese of Dublin (this is not unusual) Also if the marriage you have was RC you should look for an RC baptism of Caroline.
The address of Ryevale house struck me as Ryevale is now a common name in Leixlip (now famous as Intel produce computer chips there) there is mention of a private church there in the interesting link I attach, so the baptisms may have been there, about 40% plus of Anglican records were lost in our civil war (the public records office was hit by a shell in 1922 and one site were storing their munitions there) you could try mailing the local history section of the library to see if there are records of the house and tenants etc or the local archives, they are here http://kildare.ie/Library/LocalStudiesGenealogyArchives/ and some history of the area here, I like reading about the times they lived in. http://www.kildare.ie/leixliphistory/archives/leixlip_around_1798/ The rebellion of 1798 was fought on the rebels side using pikes hence the blacksmiths made them. Your Watts may have been military or just worked in the house.
Hope you enjoy the history,
Pat