Sowle is most notable for her role of Mrs. Bucket (Charlie Bucket's mother) in the 1971 film Willy Wonka & the Chocolate Factory, and her performance of the song "Cheer Up Charlie" (although dubbed by Diana Lee)in that film. Following the death of Leonard Stone in 2011 (who played Mr. Sam Beauregarde in the film), she is the last surviving parent of a child character in the film. Following the death of Gene Wilder in 2016, she became one of few living adult cast members, the others being as Tim Brooke-Taylor who played the computer scientist, Gloria Manon who played Mrs. Curtis, and three Oompa-Loompas, including Rusty Goffe.