Lea was first selected to represent Australia in Water Polo at the 2010 FINA Women's Water Polo World Cup where the team finished runners up and silver medallists. She went on to represent Australia at the 2013 and 2015 World Aquatics Championships in Barcelona, Spain and Kazan, Russia, respectively.

Following this, Lea was chosen to represent Australia at the Rio 2016 Olympic Games. The Australian Women’s Water Polo team, the Stingrays, made it to the quarterfinals against Hungary but lost in a penalty shootout. She was chosen again to represent Australia for the Tokyo 2020 Olympic, where the Stingrays finished fifth.