Jefferson received her Bachelor of Arts from Brandeis University, where she graduated cum laude, and her M.S. from Columbia University. She became an associate editor at Newsweek in 1973 and stayed at the magazine until 1978. She then served as an assistant professor at the Department of Journalism and Mass Communication at New York University from 1979 to 1983 and from 1989 to 1991. Since then she has taught at Columbia University, where she is now Professor of Writing. She joined the Times in 1993, initially as a book reviewer,then went on to win the Pulitzer Prize for Criticism.