Shelda turned from indoor volleyball to beach volleyball when she was 18 years old. That same year, 1991, she was a passenger in a car that was hit by a drunk driver. She endured muscle damage and the nerve in her right hand was severed. A doctor told her that she would have to give up volleyball. Instead, after an operation, she learned to hit with her left hand, and she returned to the beach. She and her partner, Adriana Behar, soon dominated the sport, eventually earning twice as much money on the world tour than any other women's team.

They won the world championship in 1999 and entered the 2000 Olympics as the favourites. They won their first four matches and then, in the final at Bondi Beach, faced Australians Natalie Cook and Kerri Pottharst, whom they had beaten 14 of the 17 times they had played. Although Shelda and Adriana Behar led in both sets, they lost 11-12, 10-12.They rebounded to win the world championship again in 2001. At the 2004 Athens Olympics, they swept through their first six matches, including a quarterfinal victory over 1996 Olympic champion Sandra Pires and her partner Ana Paula and a semifinal win against Natalie Cook and her new partner Nicole Sanderson. Shelda and Adriana Behar were beaten in the final 17-21, 11-21 by Americans Kerri Walsh and Misty May, however they became the first beach volleyball pair to earn medals in two Olympics.