2014–15 season was the most successful as of January 2018. That season she had 4 individual podiums and finished third in World Cup classification, being the second ever Ukrainian biathlete to finish a season in Top-3 after Olena Zubrilova. After Christmas Valja together with Serhiy Semenov she won World Team Challenge. The most memorable achievement was victory in mass start at 2015 World Championships in Kontiolahti, Finland. Next two seasons weren't very successful due to illnesses and weak physical conditions. Valja was forced to miss a lot of races.