Du Plessis is a legal academic specializing in the right to freedom of religion or belief and freedom of expression in European and international law. Her responsibilities include conducting legal analysis, research and drafting, as well as public speaking engagements. 

Prior to joining ADF International, Du Plessis worked in academia as a university lecturer and postdoctoral researcher in South Africa and Belgium. She taught courses on constitutional law, law and religion, international law and legal methodology. She has also published academic articles on the right to freedom of religion or belief, religion in education, and the right to life in journals such as Journal of Church and State, Human Rights Review and Journal of Religious History.

Du Plessis completed her LL.B and Master’s in South Africa and obtained her PhD (in law) at the University of Antwerp in Belgium, specializing in religious freedom rights in education.