Clijsters's sister Elke, who is younger by a year and a half, was also a promising tennis player. Like Kim, Elke won two junior Grand Slam doubles titles. She was also the ITF World Junior Doubles Champion in 2002. On the professional tour, she achieved a top 400 ranking in singles and a top 250 ranking in doubles. Kim and Elke entered one doubles tournament together on the WTA Tour at the 2004 Diamond Games in Antwerp. They won their opening match against Selima Sfar and Caroline Vis before losing to the second-seeded team of Émilie Loit and Petra Mandula in the next round. Elke retired in 2004 at age 19 due to persistent back problems.