Jefremenkowa started the World Cup in Dresden for the first time in February 2016 and finished in 19th and 13th place over 1500 m. At the following World Cup she achieved her first podium finish in the World Cup with second place in the relay in Dordrecht . At the 2016 World Championships in Seoul , she won the bronze medal with the relay. In the 2016/17 season she finished in the top ten six times in the individual World Cup, including second place over 1500 m in Minsk and thus achieved fifth place in the World Cup standings over 1500 m. At the Junior World Championships in Innsbruck in January 2017 , she won the silver medal with the relay. In March 2017 she was sixth with the relay at the World Championships in Rotterdam . In the 2017/18 World Cup season she came third in Budapest and second in the relay in Seoul. At the 2018 European Championships in Dresden, she won the gold medal with the relay and also achieved tenth place in the all-around event. At the season highlight, the 2018 Winter Olympics in Pyeongchang , she came in tenth place over 1000 m and fifth place with the relay. Her best placings at the 2018 World Championships in Montreal were 14th place over 1000 m and seventh place with the relay.
In the 2018/19 season, Yefremenkova won two times with the relay and the mixed relay. In addition, she was second and third in the relay and over 1500 m and reached fourth place in the World Cup over 1500 m at the end of the season. At the 2019 European Championships in Dordrecht , she won the silver medal with the relay. In the all-around competition, she came tenth there. In March 2019, she won the silver medal with the relay at the World Championships in Sofia and took 15th place in the all- around competition. At the Winter Universiade 2019 in Krasnoyarsk she won the bronze medal over 1000 m and 1500 m, the silver medal over 500 m and the gold medal with the relay. The following season she came in second place four times with the season and finished first in the season in Salt Lake City . In addition, she was third in the 1000 m in Montreal . At the European Championships 2020 in Debrecen , she won the bronze medal with the relay.