Cox appeared for the national team at the 2002 Commonwealth Games and played after half-time in the double over-time final win over New Zealand. She appeared for Australia in the 2003 Netball World Championships, and played the last quarter of the grand final loss by two goals to New Zealand. Cox also played for Australia's successful team at the 2007 World Championships in Auckland. Cox was vice-captain in Australia's successful campaign in the 2011 World Netball Championships in Singapore, after Natalie von Bertouch replaced the injured Sharelle Mcmahon as captain. After von Bertouch was injured, Cox became captain for the series against New Zealand and England in October 2011. During the tournament Cox scored her 2000th goal for Australia