Sullivan is an Assistant Professor of Psychology at Santa Clara University. She is a clinical psychologist who has focused on intimate relationships in her research and clinical work. She obtained a B.A. degree in Psychology with honors at Loyola Marymount University, M.A. and Ph.D. degrees in Clinical Psychology from the University of California, Los Angeles and completed a clinical internship at Kaiser Permanente in Los Angeles, where she implemented a new program for couples to assist them in their relationships and prevent future dissatisfaction and divorce.