In 2009 Hirsch was elected to the European Parliament as the leading candidate of the Free Democratic Party in Bavaria and number 9 on the Federal list of candidates. A member of the parliamentary group Alliance of Liberals and Democrats for Europe, she served as vice-chairperson of the European Parliament Committee on Employment and Social Affairs and as substitute in the Committee on Culture and Education. In addition to her committee assignments, Hirsch was a member of the Delegation for relations with the US, the Delegation for relations with the Arab Peninsula and the Delegation for relations with the countries of South Asia.
Having missed re-election in 2014, Hirsch returned to the private sector and took on a position as deputy managing director at Handelsblatt Global Edition. She later worked as Head of Communications at Raisin, a European fintech company. In 2017 she set up her own startup, Coachoo, in Munich.