Kim announced on Friday that she and her husband had welcomed baby no. 4, their second son, via surrogate, but her mother has not yet met her new grandson.
The 46-year-old actress, who in October revealed her diagnosis with multiple sclerosis, an incurable disease, reunited with friends Sarah Michelle Gellar and Kris Jenner at the annual event.
Many had voiced skepticism about the title Forbes magazine had given the Keeping Up With the Kardashians star and Kylie Cosmetics founder, noting that she was born into a rich family.