Johansen, who competes for Østre Toten Skilag, took part in junior races from 2013 to 2017. In March 2014 she became Norwegian junior champion over 7.5 km classic in Mo i Rana . At the European Olympic Winter Youth Festival 2015 in Steg she won the silver medal in the mixed relay and the gold medal over 7.5 km classic. In addition, she was there seventh over 5 km freestyle and fifth in the sprint. At the Nordic Junior World Ski Championships in 2016 in Râșnov , she won the silver medal with the relay and the gold medal over 5 km classic. In the 10 km freestyle race, she finished sixth there. The following year she won the silver medal in the 5 km freestyle and the gold medal in the skiathlon at the Nordic Junior World Ski Championships in Soldier Hollow . In addition, she came in 11th place in the relay and eighth place in the sprint. In March 2017 she became Norwegian junior champion over 5 km classic in Harstad . She ran her first race in the Scandinavian Cup in December 2017 in Vuokatti , which she finished in 32nd place over 10 km freestyle. She made her debut in the World Cup in March 2018 in Oslo , which she finished in 34th place in the 30 km mass start race. After finishing 42nd in the Lillehammer Triple at the start of the 2018/19 season, she took her first World Cup points in Beitostølen with 24th place over 15 km freestyle. At the U23 World Championships in Lahti in 2019 , she was tenth in the 10 km freestyle and fifth in the 15 km mass start race. In the following year she won the silver medal over 10 km classic and the gold medal with the relay at the U23 World Championships in Oberwiesenthal . In addition, she achieved 19th place in the 15 km mass start race.