Petra's modeling career started after she accepted a request to appear in a German magazine after appearing as an extra in
Dallas (1978). A topless photograph of her was used in the magazine, despite Petra being told the photo was meant to be a personal photo, and not intended for the magazine. However, her career only took off when she had been photographed on holiday at Cap d'Agde, and
Kate Sturdy, the then editor of H&E Naturist, saw the photo and had Petra appear in, and write for, numerous issues in the 1990's.
