Did you know that the older sister of the Kardashian family, Kourtney, and the younger, Kylie, are 18 years apart? Here’s our guide to the ages of ALL members of the celebrity clan! The matriarch of the family, Kris, is 67. Her oldest daughter, Kourtney, is 43 years old. What ages are her kids and her other famous sisters? Check out this video to find out whom out of Kris’s 11 grandkids is the youngest one!