In the 2018/19 season, Hiernickel achieved eight top ten placements, including third place in the 15 km mass start race in Nové Město , and second place in the overall ranking of the Alpine Cup. At the U23 World Ski Championships in Lahti in 2019 , she finished 19th in the 15 km mass start race and 13th place over 10 km freestyle. At the season highlight, the Nordic World Ski Championships 2019 in Seefeld in Tyrol , she was tenth with the relay.
Hiernickel has won ten medals at Swiss championships so far. In 2015, 2016 , 2018 and 2019 , she became the Swiss champion in pursuit. (Status: end of season 2018/19)