Kronenberg is best known for being Harvey Milk's campaign manager during his historic San Francisco Board of Supervisors campaign in 1977 and his aide as he held that office until he and mayor George Moscone were assassinated. As an openly lesbian political activist, Kronenberg was noted for her instrumental role in the gay rights movement, both for Milk's campaign and in her own right,
Kronenberg appeared in the 1984 documentary film The Times of Harvey Milk and her role in Milk's life was portrayed in the Academy Award-winning 2008 film Milk. Kronenberg was one of the grand marshals of the 2009 New York City LGBT Pride parade, joining the film's writer Dustin Lance Black and AIDS activist Cleve Jones who also worked with Milk.
Kronenberg is currently the executive director of the San Francisco Department of Emergency Management, and she is known globally through her public appearances and as co-founder of the Harvey Milk Foundation.