She was born in Rome on 15 January 1969[1] and graduated with a degree in Political Science from the Libera Università Internazionale degli Studi Sociali Guido Carli of Rome. She received a doctorate from the Pontifical University of Saint Thomas Aquinas (Angelicum), where she was later appointed professor of Welfare Economics and Sociology of Economic Processes.[2][3] She also studied organizational behavior at the University of Hartford (Connecticut), receiving a masters degree in 2001.[4]
On 4 November 2021, Pope Francis appointed her to be the first woman to hold the office of Secretary General of the Pontifical Commission for Vatican City State.[5] He noted that since she held the number two position in the governorship of Vatican City, Petrini had become the highest-ranking woman in the world's smallest state.[6]