The daughter of Hajo Holborn, a professor of European history who fled to America from Nazi Germany, and of Annemarie Bettmann, a philologist, she graduated from Bryn Mawr College and travelled to Oxford as a Fulbright scholar. She met and married Charles Montgomery Gray in 1954 while both were graduate students at Harvard, and earned a PhD from Harvard University in 1957, and taught there, becoming an assistant professor in 1959.
She moved to Chicago when her husband obtained a position at the University of Chicago and she herself obtained a position there, becoming a tenured faculty member in 1964.
She came to prominence as an administrator when she was appointed to a committee to investigate whether a sociology professor had been denied tenure because of her gender and political sympathies.
She was named dean of the College of Arts and Sciences at Northwestern University in 1972, and became professor of history at, and Provost of, Yale University in 1974. She was acting President of Yale University for fourteen months.
She retired in June 1993.