She earned her B.A. from St. Olaf College in Minnesota, an M.A. in history at Indiana University, a J.D. from New York University Law School, and an M.S. in fire protection management from City University of New York.

In 1977 the New York Fire Department (FDNY) for the first time allowed women to test for firefighter positions. Berkman, then an attorney, was one of five hundred women who passed the written test. Then FDNY changed its scoring system for the physical test from pass-fail to a rank-ordered test. (One personnel department official openly described it as the toughest test the department had ever given.) Berkman was one of 90 women who took and failed the test.

On behalf of herself and the other women, she filed complaint with the city. Her goal was to determine the legality of the test and to find out if it truly measured the real abilities that the job demanded. She and her attorney tried to work with the personnel dpartment to develop a fairer test, but this offer was refused, and the matter went to court.

In 1982 the court ruled that the FDNY's physical abilities test violated federal law and ordered the department to develop a new test, which all of the plaintiffs would be allowed to take. Of that group, 41 women were eventually hired. Five were fired out of training (three of whom were later reinstated), and several others resigned. For many years, the women in this class were the only female firefighters in the department.

Berkman worked as a member of the FDNY for 25 years and retired in September 2006 with the rank of captain (only the third woman to achieve that rank). Throughout her career and after retirement, she has been active in firefighter recruitment and in pre-training programs.

Berkman is a founding member and former president of the United Women Firefighters (1982–1986) and served as a trustee of the Women in Fire Service (1983-1992). She taught at the FDNY fire academy and the United States National Fire Academy.

Her many awards and honors include the Susan B. Anthony Award from the National Organization for Women (1984), a Revson Fellowship on the Future of the City of New York, from Columbia University (1987-1988); the Distinguished Alumni Award from St. Olaf College; and the Women of Courage Award from the National Organization for Women (2002). For her support of labor history and labor archives, she was honored by the New York Labor History Association in 2005.

Berkman was a featured participant in the PBS program "Sex, Power, and the Workplace" (1992), and she was the subject of the off-Broadway play "Firework" (2002). She and other FDNY female firefighters were profiled in the PBS documentary Taking the Heat (2006). National Public Radio's Debbie Elliot interviewed Berkman about the film and her experiences.