Mohlin made her debut in the Cross-Country World Cup in February 2012 in Szklarska Poręba , where she reached 36th place in the sprint. She achieved her first World Cup point in March 2014 in Lahti with 30th place in the sprint. Mohlin achieved her best result in a World Cup distance race a day later, also in Lahti, with 49th place over 10 km freestyle. In the Scandinavian Cup she achieved her best result with seventh place in the freestyle sprint in Jõulumäe in February 2015. With eighth place in the sprint in Albu in February 2012 and ninth place in the 10 km mass start race in classical technique in Otepää in February 2014 they also got two other top 10 placements. In September 2015 she won the bronze medal in the 10 km mountain run at the Rollerski World Championships in Val di Fiemme . In the 2016/17 season she finished in the top ten three times in the Scandinavian Cup and thus reached eighth place in the overall standings. In February 2017 she won her first World Cup victory in Pyeongchang together with Maria Nordström in the team sprint.