De Silva qualified for the women's 50 m freestyle at the 2004 Summer Olympics in Athens, by receiving a Universality place from FINA, in an entry time of 28.48. She challenged seven other swimmers in heat four, including 31-year-old Melanie Slowing of Guatemala. She raced to seventh place by two tenths of a second behind Nicaragua's Geraldine Arce in 28.93. De Silva failed to advance into the semifinals, as she placed fifty-second overall out of 75 swimmers on the last day of preliminaries.