Kylie Jenner believes her sister Kendall Jenner is growing up ‘too fast’

Kylie Jenner believes her sister Kendall Jenner is growing up "too fast".

The 19-year-old ‘Keeping Up With the Kardashians’ star has revealed her and her older sibling have "dreamt" for the year they would turn 21 and 19, but now the time has come the youngest of the Kardashian/Jenner brood cannot believe where the time has gone.

The television personality took to social media to pen a heartfelt birthday message to the 21-year-old model, who reached the milestone on Thursday (03.11.16).

Alongside a picture 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 & 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 @kendalljenner (sic)."

The Kylie Cosmetics founder also shared an image of her cuddling Kendall, which saw her admit to needing the brunette beauty in her life.

She wrote: "Every Kylie Needs A Kendall (sic)."

However, Kylie wasn’t the only one to shower the catwalk icon with praise and birthday wishes on her special day, as Kendall’s older half-sister Khloé Kardashian, 32, also gushed about her on social media.

She wrote: "In every lifetime I’m choosing to have you as my sister and best friend! Happy birthday @kendalljenner (sic)."

Meanwhile, the television personality celebrated her 21st birthday at Catch in West Hollywood, California, on Wednesday (02.11.16) where she was joined by her family, including Kim Kardashian West who gave her an "expensive" piece of jewellery.

Speaking previously about the 37 year old’s gift, an insider said: "Kim gave Kendall an expensive piece of jewellery and a card."