She served as an Assistant United States Attorney in the Civil Division of the Department of Justice in Washington, D.C., from 1983 until 1987.

[2] Williams was appointed to the United States Court of Federal Claims on July 21, 2003 by President George W. Bush.

She was a member of the ABA President's Task Force on Government Lawyers from 2000 to 2001 and was elected a Life Fellow of the American Bar Foundation in 1985.

Williams has also served the Bar Association of the District of Columbia in many capacities, as its Foundation president, as a trustee, and as a member of its board of directors.

In addition, Williams was chair of the D.C. Young Lawyers Section, secretary of the D.C. Bar, and a member of the Policy Board for Legal Counsel for the Elderly.