The model was spotted with the Phoenix Suns shooting guard were photographed this weekend at Soho House's Malibu branch.
Jenner, 26, and Booker, 25, were previously believed to have called it quits on their two-year relationship — but a source told E! News that they "had great energy between them" during Sunday's reunion at the members-only club.
"They shared things on their phones and laughed," said the E! source. "Kendall was looking up and smiling at Devin."
Entertainment Tonight first reported on June 22 that "Kendall feels like they're on different paths." Another source told the outlet that the pair, "have had discussions about their future but they are not on the same page."
A third source told E! News that "Kendall and Devin hit a rough patch recently and have been split for about a week and a half."
On a recent episode of The Kardashians, Kendall explained how she feels as the only Kardashian-Jenner sister without a child. "I can't believe there's another kid. It's just so many kids," she told sister Khloé Kardashian of Kylie Jenner's second baby.
While shopping for her new nephew's gift, Kendall added, "Oh my god, being in a baby store feels real for me these days. Just like the day is coming for me."
Mom Kris Jenner has more than implied that a child could be the next step for Jenner, too. "I was just thinking, maybe it's time to, you know, have a baby," Kris told Kendall during an episode of the show. In response, Jenner choked on her water.
"You keep telling me, 'You're not getting any younger,' but guess what? It's my life. I don't know if I'm ready yet," Kendall told Kris.
"I still have a lot to figure out before I can welcome a child into my life," she added in a confessional. "I'm still enjoying life on my own. And I'm okay with that right now.