She was educated at the University of Virginia School of Nursing, graduating in 1952.
She was a supporter of the African-American Civil Rights Movement. During the 1960s, she moved to Mississippi to support public school desegregation. Derian helped organize the Loyalist Democrats (not to be confused with the Mississippi Freedom Democratic Party) as a challenge to the state"s all-white official delegation and was elected as one of Mississippi"s delegates to the 1968 Democratic National Convention.
During the 1976 presidential election, Derian was deputy director of the Carter-Mondale campaign.
President Carter, however, had the post elevated to that of Assistant Secretary of State for Human Rights and Humanitarian Affairs effective August 17, 1977, and Derian served in that capacity for the remainder of the Carter administration. In this post and as head of the new Bureau of Human Rights and Humanitarian Affairs in the United States Department of State, she worked to improve policy coordination on humanitarian issues such as human rights, refugees, and prisoners of war.
In 1978, Derian married Hodding Carter III, who was then Assistant Secretary of State for Public Affairs. Derian was a vocal critic of Jeane Kirkpatrick and of the so-called Kirkpatrick Doctrine during the 1980s, which advocated support of anticommunist governments around the world, including authoritarian dictatorships, if they went along with Washington"s aims —believing they could be led into democracy by example.
Kirkpatrick wrote, "Traditional authoritarian governments are less repressive than revolutionary autocracies." Derian objected to Kirkpatrick"s characterization of some governments as only "moderately repressive," arguing that this line of thinking allowed the to support "a little bit of torture" or "moderate" prison sentences for political dissenters.
Derian, who had headed an Inter-American Commission on Human Rights delegation in 1979 to investigate reports of widespread human rights abuses in Argentina, returned to Buenos Aires in 1985 to testify in the historic Trial of the Juntas.
She remained active in civil rights in the 1970s, serving as president of the Southern Regional Council and was a member of the executive committee of the American Civil Liberties Union.