[2] At age 16 she started life in show business with Goldwyn Girls, a musical stock company where she met Lucille Ball, with whom she would remain friends, during production of Eddie Cantor's Roman Scandals in 1933.

She made four appearances on Perry Mason, including the role of Martha Dale, mother of the title character, in the 1957 episode "The Case of the Vagabond Vixen".

In 1958, she appeared as "Boxcar Annie" on the television western Tales of Wells Fargo in the episode titled "Butch Cassidy".

A long-time friend of Lucille Ball, Pepper was the second woman considered for the role of Ethel Mertz on I Love Lucy (after Bea Benaderet), but was passed over, purportedly due to the fact that she had an alcohol-drinking problem.

Her role as Doris Ziffel continued on Green Acres from 1965 to 1968 until health ailments finally forced her to leave that weekly series.