while improving de jongh broke her long jump personal record, and so the national junior record to a distance of 5.565 metres. due to her good results, after not even a year active in athletics, de jongh was selected to represent the netherlands at the 1950 european athletics championships in brussels in the long jump event. she was the youngest participant of the dutch team. with her age of 15 years old, she was too young by the athletics regulations, but was granted a dispensation. to feel comfortable she stayed with family members who lived in brussels, instead at a family hotel in a suburb of brussels where the dutch national team stayed. in the morning of the long jump competition she was very nervous and tried in the morning of the match to try to relax she started playing the piano, but according to herself she was still very nervous. she jumped 5.32 metres, a lot less than her personal best of 5.63 metres, and finished eighth.