At the 2013 European Junior Championships Ustinova won 5 golds (100 m backstroke, 4 × 100 m mixed medley, 4 × 100 m medley, 50 m backstroke and 4 × 100 m freestyle). At the 2013 World Junior Championships she won gold in 4 × 100 m medley, 100 m backstroke, 4x100 mixed medley, silver in 50 m backstroke and bronze in 200 m backstroke.