A two-time competitor at the Olympic Games (2012 and 2020), Jager was the women's individual champion at the 2013 World Archery Championships, an achievement for which she was awarded the Danish Sports Name of the Year prize for 2013.

[2] She was introduced to archery at the age of eight,[3] and in her youth practised in a warehouse in Tilst, a venue procured by her father using his local connections as a fruit grower in the Aarhus region.

[4] To meet her residency requirements in South Korea she undertook and completed an undergraduate degree in computer system engineering at Jungwon University.

Despite a difficult start adapting to her new environment, which she later reflected were the most challenging of her life, Jager graduated from Jungwon University and returned to Denmark in 2018 after five years in South Korea.

[3] 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.

[18] At the 2018 European Archery Championships Jager finished runner-up in the women's individual event to Turkey's Yasemin Anagoz, who outscored her in a one-arrow shoot-off.

[22] The outbreak of the global COVID-19 pandemic would later see the 2020 Olympics postponed until July 2021,[23] and at the rescheduled Games Jager was eliminated by Russia's Ksenia Perova in the second round of the women's individual event.