Princess Maria-Pia graduated from the Schule der Dominikanerinnen, run by Dominican nuns, in Vienna in 1978. She then enrolled in Columbia University, attaining the degree of Master of Arts in Political Science.
From 1984 until 1986, she worked for the United Nations High Commissioner for Refugees, and then from 1987 until 1988 for the Foreign Department of Caritas in Vienna. Since 1989, Princess Maria-Pia has been in diplomatic service of the Prinicpality of Liechtenstein, and started working for the Embassy of Liechtenstein in Vienna in 1990. From 1993 until 1996, she served as Liechtenstein's Ambassador to Belgium and the European Union.
In August 1996, she became Permanent Representative of the Principality of Liechtenstein in Vienna, as well as Ambassador and Head of Delegation to the Organization for Security and Co-operation in Europe (OSCE). In December next year, Kothbauer assumed the office of Ambassador Extraordinary and Plenipotentiary of Liechtenstein to Austria. Since July 2000, she has served as Permanent Representative of Liechtenstein to the United Nations. In April 2011, she became Ambassador Extraordinary and Plenipotentiary of Liechtenstein to the Czech Republic. She resides in Vienn