Sally Curry was a Girl Scout in the 1940s in Kansas.In the 1970s, she became a leader of a troop in Atlanta. “I still know how to do a square knot,” she said March 10 during a celebration marking the 100th anniversary of the Girl Scouts at Cumming Elementary School. “This gives me goose bumps,” she said of the event.The gathering welcomed alumnae of the organization to share their experiences with current Scouts, who had a chance to earn badges while learning about the organization’s history.