Müller grew up in Airolo in the canton of Ticino and was an alpine skier at the beginning of her sports career . She took part in FIS races , national junior races and championships from 2005 , but could not achieve any successes worth mentioning. In the 2006/07 season she switched to ski cross and finished fifth in the 2007 Junior World Championship in her place of residence. Müller made her debut in the Freestyle World Cup on December 12, 2008 in Les Contamines . She won her first World Cup points four days later with 18th place in Flaine . The best result in their first season was a seventh place in Kreischberg .
In the 2008/09 season, Müller only took part in one World Cup race due to a knee injury. In the following winter of 2009/10 she was classified five times among the top ten. The first World Cup podium was achieved on January 29, 2011 with third place in Grasgehren . In March of the same year a second place followed in Hasliberg and a further third place in Myrdalen-Voss . On February 26, 2012, Müller celebrated her first World Cup victory in Götschen . With a total of four podium places, she took third place in the Skicross World Cup ranking of the 2011/12 season.