Filina qualified for the women's 100 m breaststroke at the 2004 Summer Olympics in Athens, by receiving a Universality place from FINA, in an entry time of 1:19.49. She challenged seven other swimmers in heat one, including Bolivia's Katerine Moreno, who competed at her third Olympics since 1988. She raced to fourth place by nearly a two-second margin behind winner Moreno in 1:20.21. Filina failed to advance into the semifinals, as she placed forty-fourth overall in the preliminaries.