Rosalind Cash

From Muppet Wiki

Rosalind Cash (1938-1995) was an actress whose career endured and flourished on stage, screen, and television, despite her staunch refusal to portray stereotyped black roles. Ms. Cash was nominated for an Emmy Award for her work on the PBS production of Go Tell it on the Mountain.

Ms. Cash performed the voices for Roosevelt Franklin's Mother and his sister Mary Frances Franklin on the 1971 album The Year of Roosevelt Franklin.