In a new clip from Keeping Up With The Kardashians, the 35-year-old is seen giving Kylie a pep talk before Kanye West's New York Fashion Week show back in September.
If you remember, the show marked Kylie's first ever official modelling debut, and we thought she looked pretty at home amongst Kanye's catwalk strutters.
But it seems Kim had a few reservations about her younger sister's attitude at the time.
'I've been hearing things like, "Kylie makes people wait because she's on her phone," or if she's at photoshoots she brings a tonne of friends,' Kim tells the camera in the brand new KUWTK clip.
'So I just want Kylie to know just because Kanye is family, like, this isn't a casual situation. She has to be really professional and go with the flow.'
As a result of this, the mum-of-two is seen sitting down with Kylie and giving it to her straight.
Speaking of her designer husband, Kim said: 'You know, he's like, such a perfectionist obviously and this is a really big deal, to do a second show.'
'His first show did so well, you know, the second it's like - even that much more pressure, so I just want it to be perfect', Kim added.
Luckily, Kylie seemed humbled by the opportunity, and reassured her siste: 'No, I will, I'm so excited!'
Aw. Looks like she's not as big a diva as you might have thought, eh Kim?