Growing up in Berlin, Germany in the former GDR, "Franzi" loved swimming, joined a team and by the time the Berlin Wall came down in 1989, she was ready to burst onto the international swimming scene. At age 14, at the 1992 Olympic Games in Barcelona, she was the youngest participant of the re-united German team, and sensationally won the 200m and 100 m freestyle silver and bronze medals, as well as silver and bronze medals on Germany's medley and freestyle relays. She set the 200m freestyle World Record at the 1994 World Championships in Rome, breaking an eight-year record held by Heike Friedrich, the last of the GDR swimmers. She broke her own record in 2002 in Berlin. Overall, her 200m freestyle World Record stood for 13 years until broken by Federica Pellegrini of Italy in 2007. Franziska held the record longer than any other female in that event except for Hall of Fame swimmer Ragenhild Hveger of Denmark from 1938 to 1956.
Competing in another three Olympic Games, she won a total of 10 silver and bronze freestyle medals, the most of any female swimmer until surpassed by Hall of Farner Jenny Thompson (USA) with 12 medals, also in 2004.
Swimming for SC Dynamo Berlin, she competed at four European Championships between 1993 and 2002 winning 18 gold and silver medals. She is a three-time German Sports Woman of the Year, (1993, 1995, 2002), two-time European Swimmer of the Year and the 1993 World Swimmer of the Year.