Underhill was best known for work that challenged cultural and societal conventions of gender identity and sexuality.

[2] As a student of Minor White at the San Francisco Art Institute, she met Ansel Adams, Imogen Cunningham, Dorothea Lange, and Edward Weston, among other photographers then based in the Bay Area.

[4] Her career was paused for about 15 years after she married William Underhill in 1957 and raised their children.

[4] Underhill and Carter had previously held a commitment ceremony in 1991, before same-sex marriage was recognized in New York.

"[8] Her “Claiming the Gaze” was described as a “successful attempt to rescue the female subject from her typically objectified position within artwork.”[9] “NoMan’s Land” consisted of a series of self-portraits as various male subjects in the style of George Platt Lynes.