She made her first stage appearances at the Kammeroper Köln [de] and, while still in training, as Idamante in Idomeneo at the Hochschule für Musik Nürnberg.
At the Nuremberg State Theatre, Witkowski appeared in the following roles, among others: Countess in the marriage of Figaro, 1st Lady in The Magic Flute, Rosalinde in Die Fledermaus[2][3] and Lisa in Das Land des Lächelns.
[4] Witkowski also sang the title role in the operetta Die Csárdásfürstin at the Meininger Theater and the Landestheater Coburg in the meantime.
In November 2011, she gave a guest performance at the Robert Schumann Society in Düsseldorf as part of the song recital "Töne sind höhere Worte".
[5] However, her song repertoire also includes, in particular, Lieder of the turn of the century and of the modern era by composers like Gustav Mahler, Richard Strauss and Erich Wolfgang Korngold.