How Old Is Kylie Jenner. To begin who is Kylie Jenner? Kylie Jenner is the daughter of Kris plus Olympian Bruce Jenner. She came into this world Kylie Kristen Jenner into a family of 8 siblings from kids of her parents previous relationships. Kylie has 4 half sisters and brothers from her mom’s side in addition to 4 half sisters and brothers on her father’s side. Aunt to baby Penelope in addition to Mason Disick as well as North West, Kylie Jenner has adjusted to a very big family.