Wiedemann, who started for SG Hausham in 1986, came into the public eye in 1999 when she won the world championships in luge. She could not confirm this success in the following years and repeatedly failed in qualifying for the World Cup and major events to Sylke Otto , Silke Kraushaar , Barbara Niedernhuber , Anke Wischnewski and Tatjana Hüfner .
In 2001 she once again set an exclamation point when, surprisingly, she won the second World Cup run of the 2001/02 World Cup season in Lake Placid in the absence of the supposedly five best German female tobogganists, thus maintaining the German women's winning streak from 1997 to 2010.