What You Should Know ...

You know Kendall and Kylie Jenner, little sisters of Kim, Khloe and Kourtney Kardashian. Yup, heard of them, right? But what about Katherine Jenner? Ding, ding, ding! Well, turns out there's a mysterious, or should I say, secret Jenner. That's right, little itty-bitty Katherine Mae Jenner is the last and final member of the Jenner-Kardashian clan. (For now at least. What do you think, Kris?) She's a year younger than glamorous Kylie and three years younger than sweet, pure Kendall. But now, where has she been hiding all this time? Did the paparazzi ever find her? Well, you're about to find out.