Joan A. Hemm was born in Strawberry Point, Iowa, in 1957. She was adopted as an infant by Marie Andersen, a registered nurse, and Dean Andersen, a researcher at the University of Iowa Department of Pediatrics. She was raised in Iowa City, Iowa and graduated from the University of Iowa with a BA in journalism and mass communication.

She married Tom Hemm in 1986. Hemm worked for various telecommunications, marketing, and advertising companies, including the Bell telecommunications system. In Boulder, Colorado, she worked for a greeting card manufacturer and later, an advertising agency. She next worked at the University of Colorado as an advertising coordinator for the environmental engineering program.

Hemm was inspired by a high school drama teacher to pursue her interests in theater. In 1992, Hemm created a women's historical performance organization, The Shady Ladies of the Central City Motherlode, in Boulder, Colorado. The Shady Ladies study the history of the western United States, present book reports, and write and perform plays about women in the nineteenth-century West. According to Hemm, "We talk about birth control, which piques everyone's interest. We talk about how options for women were very limited during Victorian times, that a woman was the property of her husband, that she didn't have the right to vote. It's exciting that we can make history interesting."