Jager made her first appearance for the Danish national team at the 2009 Archery World Cup. She later participated in the 2010 European Archery Championships and the 2011 World Archery Championships, where she finished ninth overall in the women's individual competition. The following year she made her Olympic debut at the 2012 Summer Olympics in London. She and teammates Carina Christiansen and Louise Laursen comprised Denmark's three-person entry for the women's team event, the nation's debut in the discipline. In the preliminary ranking round, which determined the seedings for the subsequent elimination rounds, the trio set a new Danish national record of 1,946 points over the 216-arrow contest, finishing with the eighth seed of the twelve competing nations. Victory over India in the first knockout round saw them advance to the quarter-finals, where they were eliminated by South Korea.