New auntie Khloe Kardashian has expressed her delight at the arrival of sister Kourtney’s baby on Sunday.

Taking to her blog, Khloe told her fans that the whole family is gushing over the new arrival.

“I’m an auntie again!!!!!!!!!! As I’m sure you all know, my beautiful sister gave birth yesterday to the most perfect baby girl you’ve ever seen – Penelope Scotland Disick,” she said.

Khloe continued: “The entire family is literally exploding with joy and have not stopped fawning over our new little girl. And Mason is already loving being a big brother!

“This is just such a special and happy time for my family. Thank you to Kourt and Scott for making such beautiful babies! LOL.”

Khloe isn’t the only sister excited by the new arrival. Kim tweeted to her millions of followers about the arrival of the new baby.

“She is absolutely perfect! I am so excited to be an aunt again and can’t wait to spoil little Penelope. I know Mason is going to be the best big brother in the whole world. Congratulations Kourtney and Scott. Xo”

We love the name Penelope and we're sure this baby is set to be spoilt!