Phelan drove into the top three in her first FIS race , a slalom in Val Saint-Côme on December 16, 2006. The first victories followed a year later. It started in the Nor-Am Cup for the first time in January 2007 and in the 2007/08 season it was already regularly at the start in this racing series. After several top 10 results, she was third in the Mont Sainte-Anne slalom on January 6, 2008 for the first time on the podium. On the other hand, she lacked consistency in the 2008/09 season and was only once among the top ten. At Junior World Championships she only managed a top 10 result when she was fifth in slalom in 2011 .
On December 13th, 2009 Phelan celebrated her first victory in the Nor-Am Cup in Panorama slalom , three more top 10 placings followed during the rest of the 2009/10 season . Two weeks earlier she had taken part in a World Cup race for the first time in Aspen . Until the end of the 2011/12 season she remained without points in her World Cup starts, but she was still used in the giant slalom at the 2011 World Championships in Garmisch-Partenkirchen , where she failed in the first round. On November 10, 2012 Phelan drove to the 28th place in the Levi World Cup Slalom , winning World Cup points for the first time. In the World Cup season 2012/13 you get two top-10 results, you Bestresultat is a (split) ninth place on 29 January 2013 City Event of Moscow .
Ski cross
Frequent failures in the two following winters prevented further progress in the alpine area. After taking part in two ski cross races in 2014, Phelan decided to finally switch to freestylers for the 2015/16 season . She made her debut in the Freestyle World Cup on January 16, 2016 at Watles , where she finished 17th and immediately won her first World Cup points. In the 2016/17 season she was among the top ten seven times in the World Cup. She achieved her first World Cup podium on December 12, 2017 with third place in Arosa . At the 2018 Winter Olympics in Pyeongchang , she won the silver medal behind her compatriot Kelsey Serwa .