After completing her graduate degree in 1984, Mary began work for Cass County Mental Health Association and then went on to The Jacksonville Area Council on Alcoholism in 1985, where she developed the family program and facilitated individual and group outpatient therapy. During this time, she also taught at Illinois College and UIS as an adjunct faculty.

From 1987 to 1999 she held various positions at St. John's Hospital, primarily on the chemical dependency unit working with patients and family members with addictions, dissociative disorders, trauma, depression and anxiety. She also developed and conducted a group therapy program dealing with eating disorders for the Wellness Center.

Since 2003, she has been an instructor for the Prison Fathers Program at both Jacksonville and Lincoln correctional centers, facilitating a group of 14-18 inmates on parenting. From 2007, she has been presenting seminars for the Academy of Addictions Treatment Professionals (AATP) in Chicago and Springfield training therapists. She has also been regularly scheduled as a speaker for the Jung Society of St. Louis. In 2016, she was asked to join the Ornish Lifestyle Medicine Program of the Prairie Heart Institute in Springfield as the Group Support Specialist. She continues in her private practice which began in 1993, with offices in both Springfield and Jacksonville, IL. She has made her home in central Illinois and has raised three children.