The Deutsches Theater reopened in September 1945 under the leadership of Gustav von Wangenheim, and she was a member of the company.

She appeared as "Recha" with Gerda Müller in a production of Lessing's Nathan the Wise at the Deutsches Theater, Berlin.

[1] Poschmann had a leading role in the film Raid, alongside Paul Bildt, which was released in 1947.

She was interviewed in detail about this role as part of the DEFA culture film documentary Der Augenzeuge.

She also took radio roles, where she mostly also interpreted classical stage characters such as "Olivia" in Goethe's Groß-Kophta (Berliner Rundfunk 1948), "Klärchen" in Goethe's Egmont (Berliner Rundfunk 1949), "Julia" in Shakespeare's Romeo and Juliet (NWDR 1950), and "Klara" in Friedrich Hebbel's Maria Magdalene.