No, seriously, she was very well-known. See?
She is no singer -- though oddly was also in a later musical, Look to the Lilies, based on the film Lillies of the Field, as the Mother Superior. But she is a joy in the role and has several show-stopping numbers, showing that performance can overcome limitations. Yet the strangest thing is that it's her vibrant performance which is credited as one of the main reasons the musical wasn't a bigger hit, running 267 performances. The role she plays, Aunt Sissy, is a secondary character, but she was so good (and such a known name) that the show got re-shaped a bit to feature her, imbalanced the story.
Still, what remains is her wonderful performance. Her song, "He Had Refinement," has somewhat had an afterlife and is still known in various circles. This song, though, is largely lost to the ages, but it's an adorable joy. The charming score is by the great lyricist Dorothy Fields and composer Arthur Schwartz. (The book, by the way, was co-written by the legendary George Abbott and the novel's author, Betty Smith.)
And this is Shirley Booth singing "Love is the Reason."