"She's like more than half way in, so you know, we're trying."
Kardashian added that she thinks it would be "fun" for all of her sisters to be pregnant at the same time.
"There's a lot of craziness in the house, so why not add pregnancy hormones to the craziness?" Kardashian told ET with a big smile. "It would be fun. It would be like a partner in crime, someone to know those cravings that you're really going through."