Demi was born in Sittard on August 1, 1993. She was raised in Nieuwstadt, with only 3 years old she had her first training with an half squash racket. The following years she was playing tennis in TC Born. At 8 years she started to train in LTA with Tom Devries. At this moment Demi is still training at LTA in Maaseik. Demi was an active kid and combined tennis and football from her 6 till 12 years. With the higher risk for injuries in football she decided to stop and moved her focus for 100% to tennis.
From her 17th on Demi started to play professional. Nice to know is that she spends more time with the Belgians then with the Dutchies. This explains also her Belgian accents when you have a conversation with her. In 2011 she reached one of her career highlights as she qualified for all 4 Grand Slams junior finals in doubles, and she wins Australian Open and US Open. What was even more special is that she did this with 4 different doubles partners.
When on her 18th she had to move up from juniors to seniors, she had to start from the beginning again down from the bottom but her hard work payed off. As in 2012 she got selected for the Netherlands FedCup, ‘’for my feeling that’s where my tennis career really started’’. In 2015 she choose to put her focus 100% on doubles, what turned out as a good choice because later that year she wins her first WTA in Katowice and a second one in WTA Boekarest. From then on she competed in the main draw from the Grand Slam events. At this moment she is ranked 8th in the world doubles ranking (September 2, 2019).