Schäfer had a fairly successful Junior career. She was the alternate on the Swiss team (skipped by Silvana Tirinzoni) that won the 1999 World Junior Championships, but she did not play any games. Schäfer skipped the Swiss team at the 2000 and 2001 World Juniors, finishing fourth and winning the bronze medal respectively. In 2000, She lost to the U.S. team (skipped byLaura Delaney) in the bronze medal game, 8–5. She had to beat Moe Meguro's Japanese team to capture the bronze in 2001, winning the game 5–4.
In 2007, Schäfer joined Ott's team. They finished in fourth place at the 2007 European Curling Championships. They avenged their defeat at the 2008 Ford World Women's Curling Championship when the won the bronze medal, once again she had to beat Japan and their skip, Meguro. The Japanese had beat them in the 3–4 game, but in the bronze medal rematch, had slipped.
At the 2010 Vancouver Olympic Games, her team, again skipped by Mirjam Ott, finished a disappointing fourth place, as Ott's touch completely deserted her late in the semi-final and bronze medal matches.
In 2008, Schäfer has played in the Continental Cup of Curling.
|1998–99||Silvana Tirinzoni||Michèle Knobel||Brigitte Schori||Martina von Arx||Carmen Schäfer||1999 WJCC|
|1999–2000||Janine Greiner||Carmen Schäfer||Jacqueline Greiner||Barbara Appenzeller||Anna Neuenschwander||2000 WJCC|
|2007–08||Mirjam Ott||Carmen Schäfer||Valeria Spälty||Janine Greiner||Carmen Küng||2007 EC, 2008 WCC|
|2008–09||Mirjam Ott||Carmen Schäfer||Valeria Spälty||Janine Greiner||Carmen Küng||2008 ECC, 2009 WCC|
|2009–10||Mirjam Ott||Carmen Schäfer||Carmen Küng||Janine Greiner||Binia Feltscher-Beeli||2009 ECC|