Nicknamed "La Sirena de Oro" (The Golden Mermaid), she represented her native country at three consecutive Summer Olympics, starting in 1996.

In 1999, when she was 17 years old, Eileen participated in the 13th Pan-American Games celebrated in Winnipeg, Canada, in the 50-metre freestyle where she achieved a historic silver medal.

It was the first silver medal in the history of the Panamanian swimming team in these games, and she registered her best personal mark up until that moment: 25.78 seconds.

She was beaten by American Kara Lynn Joyce, who won gold with a time of 25.24 seconds.

[2] At the 2003 Pan American Games in Santo Domingo, she won a bronze medal in the 50-metre freestyle.