After two podium finishes on the Ski Cross Europa Cup circuit, Kennedy-Sim made her debut on the FIS Freestyle Skiing World Cups in Deer Valley Resort, USA in 2008 finishing 20th. Kennedy-Sim has been competing on the FIS Freestyle Skiing World Cup tour for three years placing in the top 5 on the World Cup tour. In 2011, she competed at the FIS Freestyle World Ski Championships. Kennedy-Sim, finished her 2012 season being ranked 12th in the world. She competed for Australia at the 2014 Winter Olympics in the ski cross events.