Professor McMullen earned her JD from Yale Law School and received an MS in Clinical Mental Health Counseling from Marquette University. She teaches in the areas of Family Law, Trusts & Estates, and Alternative Dispute Resolution. Professor McMullen's specialties are child protection law and divorce law, and she pursues an interdisciplinary approach, using social science research to inform legal analysis. She is advisor to the Children & Family Law Society at the Law School.
In January 2020, Professor McMullen completed two terms of service on the Wisconsin Board of Bar Examiners, serving as Chairperson in 2019. Before joining the Marquette faculty, she was a Teaching Fellow at DePaul College of Law. She also practiced law in Chicago at the firm of Sidley & Austin, where she specialized in estate planning.