Muller qualified for the 2008 Summer Olympics in Beijing, after placing ninth from the FINA World Open Water Swimming Championships in Seville, Spain. Muller swam in the first ever women's 10 km open water marathon, against a field of 24 other competitors. Muller finished the race in twenty-first place with a total time of 2:02:04.1, approximately two minutes behind winner Larisa Ilchenko of Russia.