(LREM) in 2017, she first represented the 9th constituency as Jean-Marie Le Guen's substitute following his appointment as Secretary of State for Relations with Parliament by President François Hollande.

[4] In July 2019, Lang decided not to align with her parliamentary group's majority and became one of 52 LREM members who abstained from a vote on the French ratification of the European Union’s Comprehensive Economic and Trade Agreement (CETA) with Canada.

[5] For the 2020 Paris municipal election, Lang went against the party line and endorsed Cédric Villani over Benjamin Griveaux as candidate for the mayorship.

[6] In September 2020, Lang initiated a walkout of National Assembly members in protest of a woman in a hijab addressing a parliamentary commission.

[7] In February 2022, she went against the party line again and was one of six LREM legislators who supported the Republicans’ motion for a ban on wearing hijabs in sports competitions.