Sosnitskaya made her senior debut at the Russian Championships in 2013, where she won silver with her team.

She went on to make her international debut at the Anadia World Cup, where she placed eighth on vault.

At the Russian Cup in August, she won gold on floor exercise, silver in the all-around, bronze on vault and uneven bars, and placed fourth with her team and on balance beam.

In late October, Sosnitskaya was named to the Russian team for the Élite Gym Massilia in November.

[1] She went on to compete at the Brasilia Gymnasiade, winning gold with her team and in the all-around, silver on vault, and placing fifth on bars and eighth on floor.