 Fox graduated from Vassar College in 1956, and earned an LLB in 1961 from the New York University School of Law.Before returning to NYU Law, she worked in civil law for the US Attorney's office, and became the first female partner at Simpson Thacher & Bartlett.In 1978–1979 she served on the National Commission for the Review of Antitrust Laws and Procedures, and from 1997 to 2000 she served on the International Competition Policy Advisory Committee of the US Department of Justice.