She later spent half a year in Paris before moving to Berlin in 1909, where she worked as a nurse.

She took lessons at the drama school of the German Theater in Berlin, and was hired by Max Reinhardt in 1910 as an actress.

The following year she worked there in small roles, and began using the stage name Erna Morena.

Morena worked under well-known directors such as Paul Leni, Richard Oswald, Robert Wiene, F. W. Murnau, and Georg Wilhelm Pabst, and acted alongside notable actors such as Conrad Veidt, Emil Jannings, Reinhold Schünzel, and Werner Krauss.

Morena played the role of the wife of the Konsistorialrat in the Nazi propaganda film Jud Süß.