She hopes to incorporate boys' clothing into the line in the future.
"I would love to," Kardashian, 34, said, adding that she started shopping for her son Mason, now 4, when she was pregnant with him. She also has a daughter, Penelope, who is almost 2.
While Penelope is too little to have a say in what she wears, Kardashian said she "picks her battles" when it comes to dressing her son, who likes to pick out his own clothes and "surprise everyone and then come out and show us his outfit so it's really cute." But "if there's a special occasion and I really want him to wear a suit on Christmas Eve for this or that, then he so far has been good about still wearing what I want."
Kardashian would rather shop for her kids than herself. "It's just so much more fun and there's so much out there, but I'm really picky," she said, adding that she loves to put outfits together for them.
Kardashian says she and her sisters, Kim and Khloe, each bring their own sense of style to the kids' lines, with Khloe partial to leopard print and Kourtney loving butterfly motifs and neutral colors.
Kardashian also gives a thumbs-up to the new Vogue magazine cover picturing Kim embraced by her husband-to-be, Kanye West.
Vogue editor Anna Wintour defended the cover in a letter to readers, saying she likes to "feature those who define the culture at any given moment, who stir things up, whose presence in the world shapes the way it looks and influences the way we see it." Wintour called the cover "charming and touching."
Kourtney Kardashian said she was very happy for her sister. "When she told me I was just speechless and you know she looks beautiful," she said.