In 1983, now competing as Wendy Sly, she finished fifth in the finals of both the 1500 metres and the 3000 metres at the inaugural World Championships in Helsinki. She ran her lifetime bests in both events, 4:04.14 in the 1500 m and 8:37.06 in the 3000 m. Also that year, she won the IAAF World Women's Road Race Championships in San Diego contested over 10 km.