[1] Her grandmother was a prominent activist in the civil rights movement of the 1960s,[2] and from an early age, FitzGerald was introduced to a wide range of political figures.

[4] As a teenager, FitzGerald wrote voluminous letters to Governor Adlai Stevenson of Illinois, her mother's lover,[5] expressing her opinion on many subjects, a reflection of her deep interest in world affairs.

[7] She met Washington Post journalist Ward Just at a party soon after arriving in Saigon and began a relationship with him that continued until she left South Vietnam in November 1966.

[4]: 56–7  Unlike many of the male journalists, she did not report on the latest combat operations, but rather focused on the effects of the war on South Vietnamese politics and society.

[4]: 80–2  Her final story was "Behind the Facade: the Tragedy of Saigon" describing the conditions of refugees who had sought safety in the city and were overwhelming its inadequate infrastructure and funding.

At the end of the residency she lived with Lelchuk in Cambridge, Massachusetts, where he worked as an assistant professor at Brandeis University.

[4]: 168 Her book Fire in the Lake: The Vietnamese and the Americans in Vietnam was serialised in five parts in The New Yorker in its newly-created "Annals of War" series starting in July 1972 earning her a Special Front Page Award.

[9][10][4]: 204  The book cautioned that the United States did not understand the history and culture of Vietnam and it warned about American involvement there.

[11] She returned to South Vietnam in early 1974 one year after the signing of the Paris Peace Accords and twice crossed over into Vietcong controlled territory, filing stories for The New York Times and the Atlantic Monthly.

She travelled to Hanoi in late 1974 and stayed in North Vietnam into early January 1975, writing a 23-page article for the New Yorker.