Stewart, who founded the award-winning LaMaMa Experimental Theater Club, died of natural causes on Thursday (13Jan11).
Founded in 1961, the theatre gave early opportunities to acting greats such as Al Pacino and Robert De Niro.
During her 50 years as a director and producer of LaMaMa, Stewart collaborated with other artists including Sam Shepard, Bette Midler, Tom O'Horgan and more.
And she was the first off-Broadway producer to be inducted into the Broadway Theatre Hall of Fame in 1993.
Stewart is survived by her adopted son, Duk Hyung Yoo, and eight grandchildren.