She had been born in Finland but evacuated to Sweden during World War II and came to live in a village near the Norwegian border. She later married a Swede, changed her name from Karvonen to Gustafsson and took Swedish citizenship. And then began her Olympic odyssey.
She had been a good cross-country skier at school, but Gustafsson's international debut only came in 1960, at the age of 22. Two years later she was the Swedish champion and, in 1964, she was part of the relay team that won a silver medal during the Olympic Winter Games in Innsbruck. But individual medals eluded her.
Her skills and technique continued to develop and, as the athletes arrived in Grenoble, it was clear that Gustafsson would be the one to beat. She herself considered her closest rival to be the Russian Galina Kulakova, and so it proved.
Having been the final athlete to ski away from the line at the 5 km race, Gustafsson made sure she knew exactly how Kulakova's race was panning out, demanding regular updates on her rival's progress and speed. In the closing stages, she knew she was behind the pace and so Gustafsson pushed herself to the very limit over the closing kilometre of the race to win gold by just three seconds.
In the 10km race, she had a more emphatic victory, winning by eight seconds from Norway's Berit Mødre Lammedal. She finished her Games with another silver in the relay race, in which she skied the fastest leg, to return home with three medals. She retired from the sport and, with a reputation for being one of the fittest athletes in one of the most demanding winter sports, became a physical education teacher.