Jerneja Brecl started on September 13 and 14, 2014 for the first time in two competitions in Einsiedeln in the Alpencup , where she took 17th place twice. After further starts in the Alpine Cup, she made her debut almost two years later on August 26 and 27, 2016 in Oberwiesenthal in the Continental Cup , where she achieved positions 17 and 19 and thus her first Continental Cup points. This was followed by further starts in the Alpine Cup; To date (February 2018) she has won five Alpine Cup competitions.
On January 20 and 21, 2018, in Planica , she was only able to take third and fourth places in the Continental Cup, twice taking her first podium places. Then she finally made her debut on January 27, 2018 in Ljubno in the Ski Jumping World Cup and reached 27th place and thus directly her first World Cup points. At the Nordic Junior World Ski Championships in 2018 in Kandersteg , Switzerland , she was world champion with the Slovenian team. At the team competition on February 9, 2019 on the Logarska dolina in Ljubno, Slovenia, she and her teammates Špela Rogelj , Nika Križnar and Urša Bogataj reached the podium in a World Cup for the first time with second place. Later that month she finished fourth with the Slovenian women's team at the 2019 World Championships in Seefeld in Tirol, and reached 18th place in the individual.