Reality TV personality Kylie Jenner believes her sister and model Kendall is growing up "too fast", and although the pair have been dreaming of the year they turn 19 and 21, she can't believe it has finally come.
The television personality took to social media to pen a birthday message to the 21-year-old model, who reached the milestone on Thursday, reports femalefirst.co.uk.
Alongside a photograph of the sisters when they were younger, on her Instagram account, Kylie wrote: "my big sister is 21 happy birthday Kenny. My other half. I wouldn't be me if it weren't for YOU we dreamt about the day when you'd turn 21 and I'd be 19. It came too fast...
"But who you are and where you are today was beyond my wildest expectations! You are an angel my supermodel sister. I love watching you live out your dreams. Every Kylie needs her Kendall," she added.
The Kylie Cosmetics founder also shared an image of her cuddling Kendall, which saw her admit to needing the model in her life.
She wrote: "Every Kylie Needs A Kendall."