Leslie Falkenberg (November 7, 1955 - September 11, 2001) was the second of four children born to H. G. Whittington and Ruth (Simpson) Whittington. As a child, she lived in Topeka and Lawrence, Kansas. The family moved to Denver, Colorado, where she graduated from East High School in 1973. After graduation, she met Charles Falkenberg, who graduated in 1974. They married in Denver in a beautiful garden ceremony on August 11, 1984.  

She received a bachelor's degree in business from Regis College's School for Professional Studies in 1984 and received her master's degree in economics from the University of Colorado in 1987 and was awarded a doctoral degree in 1989.

In 1989, Charles and Leslie moved to Maryland where she became an assistant professor in the College of Human Ecology, later moving to the Department of Agricultural and Resource Economics at the University of Maryland.  

She became an associate professor of public policy at Georgetown University in 1997 where she was an economist who studied the effect of taxation on family behavior. She also had an active interest in tax policies and the status of women in industrialized and developing countries. She was a co-author of several papers with James Alm on the effects of taxation on marital decisions, including a 1998 study that found the federal government would gain substantial revenue if same-sex couples were permitted to marry.

On September 11, 2001, Leslie and her husband, Charles Falkenberg and two daughters Zoe Falkenberg and Dana Falkenberg , were on their way to Australia for a sabbatical and to be a visiting fellow at the Australian National University in Canberra when their plane was hijacked and crashed into the Pentagon.