Mary Lee Eggart was born and raised in Baton Rouge, Louisiana. She was educated at St. Joseph’s Academy and Louisiana State University, where she received Bachelor and Master of Fine Arts degrees in printmaking. In 2011 she retired from the LSU Department of Geography and Anthropology where she was employed for over 30 years as a research associate in cartographic design and scientific illustration and as an instructor in cartographic design. She continues to work as a consulting cartographic designer.

Eggart's drawings focus on the world of nature, which has intrigued her since childhood. She works in the drawing media, specializing in colored pencil designs featuring birds, flora, and fauna for their aesthetic appeal as well as their metaphorical significance. She is represented by LeMieux Galleries, New Orleans, and also exhibits at the Baton Rouge Gallery.