[1] The eldest of five children, her father was a Coca-Cola bottler and president of the Texas Historical Association; her mother was a stay-at-home parent with an active presence in the community.
In an interview, Dunagan light-heartedly described her extended family, "My heritage is a long line of Southern Baptist and Methodist preachers.
[4] Following her divorce, Dunagan's parents agreed to fund graduate studies at Trinity University, Texas through the Dallas Theater Center.
She made her Broadway debut in the 1979 production of George Bernard Shaw's Man and Superman at Circle in the Square as an understudy for Ann Sachs.
[6] She has worked in films including The Visit, The Naked Face, Running Scared, Men Don't Leave, and Losing Isaiah.
In 2007-2008, Dunagan returned to Broadway in the Steppenwolf Theatre's production of Tracy Letts' August: Osage County, having originated the role in Chicago.