In 1979 she took over the role that Sylvia Sidney had originated on "WKRP in Cincinnati" a year earlier as Mama Carlson, the tough-talking owner of a radio station managed by her son Arthur, played by Gordon Jump. Bruce kept the recurring role until the series ended in 1982.
http://www.latimes.com/news/obituaries/la-me-passings14oct14,1,5650179.story?track=rss
(You'll need to scroll down to reach the announcement about the passing of Ms. Bruce.)
http://www.latimes.com/news/obituaries/la-me-passings14oct14,1,5650179.story?track=rss
(You'll need to scroll down to reach the announcement about the passing of Ms. Bruce.)