The first hint of her involvement in entertainment appears to have been captured in the 1900 federal census, where her profession was given as "whistler." Some have speculated this was a job calling out to passersby to visit a nickelodeon theater. In 1909, however, the year films were first made in Los Angeles, Josephine answered an advertisement calling for a dark-featured woman for acting roles. Quickly, she became a major star in the fledgling film industry in Hollywood with her peak period of activity coming between 1913 and 1915.
Working with film director Frank E. Montgomery (a.k.a., Akley), Princess Mona made dozens of short films as a stereotypical Indian for such companies as Bison, Nestor, Kalem and Centaur and one full-length film for Universal in 1917 before she retired. While her husband continued to work in the industry as a cameraman and bit player, the former Princess lived in obscurity for decades.
She lived in the Echo Park neighborhood of Los Angeles until her death on 3 September 1977 when she was 95 years old. She died as a ward of the State of California and her collection of film memorabilia, recalled by relatives, was likely discarded as she had lost contact with her family. Josephine Workman/Princess Mona Darkfeather was buried in an unmarked grave at Holy Cross Cemetery in Culver City, California.