Cost earned a bachelor of arts in psychology at Auburn University in 1991 and began her career as a case manager and assistant program director at the East Alabama Mental Health Center in Opelika in 1992. She completed a master's in special education at Auburn in 1993 and was hired as a special education teacher for Lee County Schools and the Lee County Youth Development Center. In 1998 she completed her Ph.D. in rehabilitation and special education, also from Auburn. From there she joined the faculty of Stephen F. Austin State University in Nacogdoches, Texas. After two years there she returned to Alabama to become an assistant professor at the University of Montevallo. She was made a full professor in 2012 and appointed as Special Education Program Coordinator in 2017.
Cost is married to artist Andrew Cost and has two sons, Eli and Campbell.
- Crain, Abbey (November 30, 2019) "Mayor of Montevallo honored for promoting equality." The Birmingham News