John,
Yes, the 13 Oct 1833 Marriage in the RC parish of Powerstown, Co Tipperary is the correct marriage record for my GGGGrandparents. The witnesses to that marriage were John Luby and Bridget Connors. The couple's first child, Denis Shanahan was baptised in the same parish on 24 Aug 1834; sponsor Rev. Edmund Maher and Brigid Connors. It is my assumption that the marriage witness Bridget Connors and baptismal sponsor Brigid Connors are the same person despite her given name [Bridget/Brigid] being spelled two different ways.
Although I must say I find it very interesting that you have given the name as Thomas ShaNNahan (two N's) and his wife's first name as Mary because the Irish Family History Foundation (http://www.rootsireland.ie) gives the spelling of Thomas' surname as Shanahan (only 1 "N") and gives his wife's first name as Bridget, not Mary. Interesting because Rootsireland.ie is a transcription only site, so one cannot compare their data with the originals for any errors. However, my cousins and I contracted Catriona Crowe in Limerick to investigate for us and she too confirms the same spellings as Rootsireland and that the mother's name was Bridget rather than Mary. However, because I wasn't sure if Catriona actually had access to the original entry, I also contacted the parish priest in Powerstown and he too, after consulting his original parish records confirms that the wife's name was Bridget Luby, not Mary as you have stated.
Thomas Shanahan and Bridget Luby's second child (my GGGrandfather) Michael Shanahan was baptised in Holycross RC Parish in Co Tipperary on 14 Jan 1838 only on this record his mother's name is recorded as Bridget LOOBY rather than LUBY and lists only one sponsor by the name of Mary Looby.
Their third child Margaret "Maggie" Anne Shanahan was baptised 3 Sep 1841 in St. Patrick's RC Church in the city of Limerick. Her record is found under the spelling Margret ShaNNahan and her godparents were Thomas and Catherine Burch.
Their fourth child, Thomas Shanahan was baptised 10 Feb 1844 also in St. Patrick's RC Church in Limerick; his record is found like Maggie's under the spelling Thomas ShaNNahan and Bridget LOOBEY; with his godparents listed as Patt Fox and Honora Peckam. Both Maggie and Thomas were baptised by the Rev. George Butler. George Butler at that time (1841-1844 was not the priest at St. Patrick's but rather the curate).
These four Shanahan children were left orphaned when their parents Thomas and Bridget Luby Shanahan died during the famine. Our 'family tale' passed down for so long, says that the children were left in care of a grandparent (unknown if it was Thiomas Shanahan's mother or Bridget Luby's mother) and that the youngest son Thomas Shanahan drowned as a child in a river near their home (we assume in the River Shannon since they were living in Limerick).
Where did you find the marriage record stating that Thomas ShaNNahan married MARY Luby in 1833 in Powerstown? Thought I'd covered all the bases here, but if you found a record under Mary Luby, rather than Bridget Luby, I'd love to know what the source actually is.
Thanks for you help!
Kathy