Charles was named to the national team invited to compete at the 1992 Olympics, held in Barcelona, Spain. The USA team won their first three games, but then played the Unified Team and fell, 79–73. The USA team then faced Cuba for the bronze medal. The game was tied at halftime, and Cuba had a small lead midway through the second half, but the USA went on a run to retake the lead, and finished with an 88–74 victory and the bronze medal. Charles averaged 6.2 points per game.
Charles continued to represent the USA on the national team when it competed in the 1994 World Championships in Sydney, Australia. The team was coached by Tara VanDerveer. The team won their early games. Against Spain, Charles led the USA scorers with 18 points, helping secure the win. She also contributed 22 points to a win against the host team Australia. The team then advanced to the medal rounds and faced Brazil. Despite 29 points from Katrina McClain, the USA fell 110–107 when Brazil hit ten of ten free throws in the final minute. The USA went on to defeat Australia 100–95 to claim the bronze medal.