Glad to have helped indirectly. Now that you've found her in the index, you can get a photocopy of the actual registration from the GRO (groireland.ie) for 4 euros if you provide the date, place, volume, and page, all on the familysearch site, or order the filmed volume from the LDS for $3.50. Either way, you'll learn her parents' names, which should allow you to find their marriage and thus their parents' names.

Diane