Kardashian, 32, gave birth to her first child with rapper Kanye West June 15.
UsMagazine.com said Kardashian has been working hard to get her pre-baby figure back and has already lost 20 of the 50 pounds she gained while pregnant with daughter North West.
"She wants to show up like Heidi Klum and have everyone marvel at how fast she lost the weight," a source told the magazine. "She won't leave the house until she's thinner."
Notable deaths of 2014 [PHOTOS]