Kendall Jenner admits she "grew up too fast a long time ago."
The 19-year-old model, who shot to fame on her family's reality TV series 'Keeping Up with the Kardashians' eight years ago, claims she was "brought up to be a workaholic" by her parents, Bruce and Kris Jenner, and her older half-sisters, Kourtney Kardashian, 35, Khloé Kardashian, 30, and Kim Kardashian West, 34, and is already worried about getting older.
Writing about youth in the February issue of the Wall Street Journal magazine, the brunette beauty shared: "I feel like I grew up too fast a long time ago.
"Having older siblings, you grow up around adults, so you mature more quickly. I saw my sisters and parents working every day, so I was pretty much brought up to be a workaholic. But I just turned 19 a couple weeks ago, and I'm scared to be 20 -- it's the first step out of being a teenager."
But Kendall - who has walked the runway from Chanel, Marc Jacobs and Givenchy - revealed Khloé is always encouraging her and younger sister Kylie Jenner, 17, to enjoy their youth.
She wrote: "My sister Khloé always says to me and my younger sister, Kylie: You have your whole life to be an adult but only so long to be a kid. And we get it. In the right situations, I try to be as immature as I can sometimes -- react to things as if I were 12. You can't take things too seriously."
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