Wow, that was fast! I reported it to the moderator, and the move was made within minutes. Thanks, KarenM!
Unless you have more details than previously it's difficult to suggest new resources for your sister to check in Dublin.
I found *potential* birth records for Michael Keenan and Mary Curran, but with no other sources, I don't know how to confirm them. Thus, I'm hesitant to state that these ARE their birth records. Here's the information:
Name: Michael Keenan
Date: 9 May 1841
Parish/District: Newry
County: Down
Denomination: Roman Catholic
Father:
Terence Keenan
Mother: Elizabeth Rice
Sponsors: William McAlinden, Ellen Rice
Name: Mary Curran
Date: 11 Oct 1839
Address: Rafian
Parish/District: Drumlane
County: Cavan
Denomination: Roman Catholic
Father: Patrick Curran
Mother: Rose Curran
Sponsors: Patrick Timmins, Bridget Johnson
These dates and names roughly match up with what I have, except for the father's name of Terence. So that may completely rule it out, or may simply mean he had a name like John Terence Keenan. I was unsure of how to proceed, so had to just drop that line of pursuit for the time being.
The Irish Catholic Parish Registers have just been put online recently but you need to select a parish to start browsing the images. Did nothing ever come of the 'County Cork' possibility?
I haven't had any luck tracking down potential matches in Cork. My mother always assumed that her mother was referring to the Keenans, but it's possible that she was referring to one of the other families. Based on surname distribution, it looks like Keenan was not at all likely in Cork, but I don't want to eliminate the possibility just based on that.
From a quick look at the previous topic it was suggested that the parents' details on the marriage record are likely to be more accurate (rather than from the death details as the informant may not have known the correct information). However, it is possible that the 2 different names for the mother are both correct- if the mother did remarry after the death of her husband (another reason why informant may have given different names). Therefore, since you don't have much to start with yet it might be worth searching for a 2nd marriage of the mother and even a possible death for the father.
I'll pursue this, as I don't think I ever looked at it from that perspective.
I don't know if this is the right place to mention it, but I recently did a DNA test through Ancestry, and my mother has done one through National Geographic's Genographic Project. Not sure if either of those are likely to be of use in our search.
Thanks for your help!