[2] As a teenager she noticed her attraction to women, via crushes on stars like Katharine Hepburn, and went to Ohio State University with a girlfriend.

[2] By the end of Gittings' period as editor, Lahusen remembered there was a waiting list of women who wanted to be full-face on the cover of the magazine.

[3] She wrote articles in The Ladder under the name Kay Tobin, a name she picked out of the phone book, and which she found was easier for people to pronounce.

[8] She worked with Gittings in the gay caucus of the American Library Association, and photographed thousands of activists, marches, and events in the 1960s and 1970s.

[8] In 1970, Lahusen was part of the founding of the original Gay Activists Alliance,[11] and in 1972 worked to push the American Psychological Association (APA) to remove homosexuality from its Diagnostic and Statistical Manual of Mental Disorders.

As part of the latter, she also photographed John E. Fryer wearing the disguise he donned to protect his reputation when he addressed the APA convention as a gay psychiatrist.

[2] Recalling her work from the perspective of 2021, Kevin Jennings, head of Lambda Legal, said, "It is impossible to overstate Kay’s importance in the struggle for LGBT rights and dignity.

[8] More recently, her photographs were featured in exhibits at the William Way LGBT Community Center in Philadelphia[14] and the Wilmington Institute Library in Delaware.

[17] Lahusen was working on collecting her photographs for a photography scrapbook on the history of the gay rights movement when Gittings' illness put the plans on hold.

[18] The same year, Lahusen appeared on the podium at a Philadelphia event celebrating both the history and future of gay rights, soon after the Supreme Court ruling that legalized same-sex marriage.