Biggert was a member of the Illinois State House from 1983-1998, from district 81. She is an attorney, and was a clerk for Luther M. Swygert, U.S. Appeals Court Judge, 7th district. She received her JD from Northwestern University School of Law, 1963 (Member, Board of Editors, Law Review), and her BA from Stanford University, 1959.
She and her husband Rody have four children and many grandchildren. They are members of Grace Episcopal Church, Hinsdale, Illinois.