She is the current national and Oceanian record holder.
After winning the discus gold and shot put bronze medals at the 2005 World Youth Championships in Athletics, she went on to win the bronze medal in the discus at the 2006 Commonwealth Games in Melbourne at the age of seventeen.
She won the discus silver at the 2007 Summer Universiade and represented Australia at her first World Championships in Athletics soon after.
She reached the final of the 2008 Beijing Olympics and improved significantly the following year to win the gold medal at the 2009 World Championships in Athletics.
Samuels is one of only nine athletes (along with Valerie Adams, Usain Bolt, Veronica Campbell-Brown, Jacques Freitag, Yelena Isinbayeva, Kirani James, Jana Pittman, and David Storl) to win world championships at the youth, junior, and senior level of an athletic event.
Her personal best throws are 69.64 m for the discus and 17.05 metres in the shot put.
Samuels has also spent many winters playing basketball in the Waratah League alongside her sister, Jamie, who has played in the Women's National Basketball League.