Miriam Therese Winter ("Joy Is Like the Rain") of the Medical Mission Sisters is still going strong. She still composes, and she's a theology professor at the interdenominational Hartford Seminary, a school with Congregationalist roots. I heard her speak at the California convention of Call to Action (a bunch of us Catholic renegades), and she was really something. We have at least a couple threads on her music. I used a lot of her songs for teaching kids - they loved the songs.
-Joe-