In August 2015, the then 15-year-old made her debut in the Continental Cup in Oberwiesenthal . A month later, she celebrated a double win in the Alpine Cup in Einsiedeln . As the youngest Slovene starter, Križnar made her debut in the ski jumping World Cup on February 13, 2016 at the Logarska dolina competition in Ljubno and was 14th to collect her first World Cup points. The following day she scored points again in twelfth place. At the Nordic Junior World Ski Championships in 2016 in Râșnov , she finished seventh in the singles and became world champion in the mixed team competition with the Slovenian team.
In the 2017/18 season , Križnar reached her first top ten placement in the World Cup on December 1, 2017 in tenth place in Lillehammer . In addition, she finished fifth in Hinterzarten and two in Zaō with the Slovenian team in the first two team competitions in the women's World Cup . At the Nordic Junior World Ski Championships 2018 in Kandersteg , Switzerland , she was junior world champion both individually and with the Slovenian team. At the 2018 Winter Olympics in Pyeongchang , she was seventh best Slovenian in the individual competition on the normal hill . At the first World Cup station after the Winter Olympics in Râșnov , she achieved her first World Cup podium finish on March 4, 2018, finishing third. With 383 points, she finished the 2017/18 season in tenth place in the overall World Cup and thus achieved her best result to date.