Guerrero competed in a breaststroke double at the 2000 Summer Olympics in Sydney. She achieved FINA B-standards of 1:13.04 (100 m breaststroke) and 2:36.90 (200 m breaststroke) from the Southeast Asian Games in Bandar Seri Begawan, Brunei. On the second day of the Games, Guerrero placed thirty-fifth in the 100 m breaststroke. Swimming in heat three, she struggled to keep her pace against seven other swimmers, and raced to the last seed in 1:15.14, more than two seconds below her entry standard. Three days later, in the 200 m breaststroke, Guerrero posted a time of 2:38.10 in heat one, but finished farther from the semifinal field with a thirty-first-place effort.