I posted earlier about trying to find records for my ancestor Julia Creedan/Sister Mary Felix when she was in the Sisters of Charity. While searching for her, I ran across several Catholic Directories available for free online. These directories are a great resource if you have an ancestor that was in the Catholic clergy in the 1800s. They don't provide a listing of every name, but you might get lucky.
I found two entries for a Sister Felix in the directories for the Sisters of Charity in New York. The first entry was from page 179 of Sadliers' Catholic Directory Almanac and Ordo for 1876. In the section for Albany, there is a Sister M. Felix, superior at St. John's Parochial School.
The second entry is from page 145 of Sadliers' Catholic Directory Almanac and Ordo for 1881. This one has a Sister Felix working in St. Mary's Orphan Asylum in Rondout, New York.
I wasn't able to find a Felix or Creedan that matched my ancestor in the 1880 census for New York. Julia was from the Sisters of Charity order in Cincinnati, Ohio, so I'm finding it doubtful that either of these are her. It's still a possibility since I know they sent her out of state at various times. I really need that 1880 census entry to tell for sure!
More information on Julia's religious career is available here.