De Ridder first became a member of the Bundestag after the
2013 German federal election, representing the
Mittelems district. She was a member of the Committee for Education, Research and Technology Assessment before moving to the Committee on Foreign Affairs and its Sub-Committee on Civilian Crisis Prevention in 2018. She was the committee's deputy chairwoman until September 2021. In addition to her committee assignments, De Ridder has served as deputy chairwoman of the German Parliamentary Friendship Group with Belgium and Luxembourg (2014–2018) and the German-French Parliamentary Friendship Group (2018–2021). Since 2018, she has also been part of the German delegation to the
Parliamentary Assembly of the
Organization for Security and Co-operation in Europe (OSCE). In 2020, she joined the
Inter-Parliamentary Alliance on China. In the Bundestag election on September 26, 2021, De Ridder initially
missed re-entry into parliament; by June 2022, she took the seat of
Yasmin Fahimi who had resigned from parliament. == Other activities ==