Kim Kardashian "Can't Wait to Meet" Kourtney's Baby Girl: "The Whole Family Is So Excited!"

Reality superstar offers some public congrats to her sister and Scott Disick in wake of announcement they're expecting a daughter

It's official: when it comes to the impending arrival of Kourtney Kardashian and Scott Disick's new baby girl, the Kardashian family just "can't wait."

Khloé Kardashian Odom "can't wait" to buy her forthcoming niece a glitter tutu. Kris Jenner "can't wait" to buy her soon-to-be granddaughter something pink. And auntie Kim Kardashian? She just can't wait to meet her!

"Kourtney is having a baby girl!!!" she exclaimed in a post on her official blog this afternoon. "The whole family is so excited!

"Mason is going to have a little sister! Congratulations, Kourtney and Scott. I can't wait to meet her. Xo."

Though Kim was later than her sisters and mother in expressing public congratulations on this morning's announcement, she had a good excuse—she was on a plane, en route to filling in for the apparently under-the-weather mother-to-be.

"Just landed in Philly!" she tweeted. "I know Kourtney was scheduled to be selling live on QVC, but she wasn't feeling good, so I'm taking over!"

Aww. Forget maternal instincts, sisterly ones run just as deep in this family.