Lisa:
I did not find any more baptismal records in Enniskeane for children of Daniel Mahony and Mary Sullivan.
However, in the nearby parish of Bandon, there were four baptismal records of interest. Parents Daniel Mahony and Mary Sullivan. The baptismal records for Bandon have a gap from October 1811 thru December 1813. Was Ellen baptized in the gap period? https://registers.nli.ie/parishes/0017 By the way, all of these records are on irishgenealogy.ie
James Mahony October 30 1810
Mary Mahony August 15 1814
Daniel Mahony March 30 1816
Eliza Mahony July 10 1819
Roger