In this article (Sexy 1971, issue 5) Nevenka is introduced to us as a competition winner. Her win: an appearance in the up-coming Curd Jürgens movie
Käpt'n Rauhbein aus St. Pauli.
This seems to have come to nothing, another Sexy reader ended up in that film. However, there was a later issue reporting (with pictures proving it) that Nevenka was appearing in the softcore film
Mache alles mit. Her scenes in that film seem to have been cut though.