After appearing as Anya in Conny Walter's Wie Feuer und Flamme (2001), she was the leading Actress, playing Paula Behringer, in the ARD series Sternenfänger (2002). In 2003 she played alongside Matthias Schweighöfer as Katharina in Soloalbum, from the novel with the same title by Benjamin von Stuckrad-Barre. In 2005 she was the leading Actress, playing Titzi in Anno Saul's Kebab Connection and some smaller roles in television series including Ein starkes Team and Abschnitt 40. She was the leading Actress playing alongside Christian Ulmen in the film FC Venus – Elf Paare müsst ihr sein. In 2006 she played in the ZDF science fiction series Ijon Tichy: Raumpilot, a filming of The Star Diaries by Stanisław Lem. It won the German Television Prize and was nominated for the Grimme-Preis. In 2007 she was the leading Actress alongside Til Schweiger in the romantic comedy Keinohrhasen. For this role, she won a Bambi in the national film category in 2008. In 2012, she voiced the main role of Merida in the German dub of Brave. From 2013, Tschirner and Christian Ulmen will play a team of investigators in the Weimar-based episodes of the Tatort series. In the German version of the 2013 reboot of the video game Tomb Raider, she voices the main character Lara Croft.