 She has represented her country at the Central American and Caribbean Games (2010, 2014), the South American Championships in Athletics (2013, 2015), the Ibero-American Championships in Athletics (2010, 2014) and the 2015 Pan American Games.Middleton won her first senior medal at the 2002 Central American Championships in Athletics at the age of 14, taking the discus silver medal.She was highly successful in regional age category competitions