Prior to joining Phoenix School of Law in 2011, Professor Millar was a Staff Attorney at the United States Court of Appeals for the Eleventh Circuit in Atlanta. Her work for the Court involved the review of appeals in bankruptcy, criminal law, civil rights, employment discrimination, habeas corpus, immigration, and Social Security cases. She also volunteered with the Atlanta Community Food Bank, the Partnership Against Domestic Violence, and the Fulton County District Attorney's Teen Court Program. Professor Millar is a member of the Pennsylvania Bar.

During law school, Professor Millar interned in The Hague with Judge Fausto Pocar, then president of the International Criminal Tribunal for the Former Yugoslavia and a judge on the Appeals Chamber for the International Criminal Tribunal for Rwanda. Professor Millar also interned with the Caribbean Regional Headquarters of the United Nations Development Fund for Women in Barbados. Additionally, she was an Articles & Comments Editor for the Miami Law Review and earned membership in the Order of the Coif.

Before attending law school, Professor Millar spent ten years working as a journalist. She also served on the Board of Directors of the New York City Chapter of the National Organization for Women from 1997 to 2005. She was president of the organization from 2000 to 2002, and in 2004, she received the Susan B. Anthony Award for grassroots feminist organizing.

Professor Millar's research interests include women's rights, international and comparative law, alternative dispute resolution, and criminal law. She is the author of Envisioning a U.S. Government that Isn't 84% Male: What the United States Can Learn from Sweden, Rwanda, Burundi, and Other Nations, 62 U. Miami L. Rev. 129 (2007), and is working on an article about international parental leave policies. She recently presented a paper on juvenile justice at the Feminist Legal Theory Project's Vulnerability, Resilience, and the State Workshop at Emory University School of Law.