Early in her career she was involved in the field of integrative psychotherapy, a movement that seeks to find the best practices from among the major schools of therapy.
Kirschner has written extensively on psychotherapy integration, couples and family therapy, the treatment of sexual abuse, and the role of psychologists in family-owned businesses and the media.
A past focus of Kirschner's research has been the impact of the marital relationship on children's functioning and the common underlying characteristics of healthy marriages.
Kirschner's findings regarding the impact of marital conflict on children's adjustment are relevant to the "nature vs. nurture" controversy.
Kirschner also found that successful couples and families learned to handle conflicts skillfully to prevent lingering resentment.
Two decades of empirical research summarized by Gottman and Silver (1999),[10] Olson and Flowers[11] (over 6,000 couples studied, 1993) and a metanalysis by Bradbury, Fincham, and Beach (2000)[12] have validated Kirschner's ideas and confirmed the relational importance of commitment, conflict resolution skills, desire to spend time with each other, sexual fidelity, and lack of violence.