De Jonge made her international debut in Helsinki at the European Short Course Swimming Championships 2006.

She won a silver medal in the 4×50 m freestyle relay alongside Inge Dekker, Chantal Groot and Marleen Veldhuis.

In March 2008, during the 2008 European Aquatics Championships in Eindhoven of her home country, she swam time-trials for the 2008 Summer Olympics.

She also started in the heats of the 4 × 100 m medley relay and helped the Dutch to achieve the final spot.

[1] De Jonge was selected for the 2008 Summer Olympics in Beijing in which she formed a team with swimmers Inge Dekker, Chantal Groot, Femke Heemskerk, Linda Bank, Ranomi Kromowidjojo, Manon van Rooijen, Hinkelien Schreuder, Jolijn van Valkengoed and Marleen Veldhuis.