Haanappel began skating in 1949 at Houtrust ice skating club in The Hague. Aged 12 years, she competed at her first major international competition, the European Championships in Dortmund, where she finished 14th. She won the first of her four Dutch national titles in 1955. She finished 13th at the 1956 Winter Olympics in Cortina d'Ampezzo, Italy.