They've got to get back to their lives!

Kim and Kourtney landed back in LA last night, after spending the last 24 hours in Cleveland with sister Khloe while she gave birth to her baby girl, and the girls were pretty quick to pick up and leave on their private jet once their new niece arrived. We can't blame them, though, as they both have three kids at home to take care of!

Apparently, Kimmy K assisted during the delivery!

"@khloekardashian I’m so happy for you! Your baby girl is so beautiful! You are so strong, you made that look so easy! I can’t wait for our baby girls to grow up as best friends the way we are! I’m so happy I was able to return the favor of holding your leg while you pushed LOL,” she tweeted confirming the happy news.

The K clan is said to be furious with Khloe's cheating boyfriend Tristan Thompson, and you just know they're going to make his life difficult from here on out.

They are said to be trying to be "supportive" of any decision the Revenge Body star makes regarding her relationship, but behind the scenes, they're all praying she dumps him and doesn't drag things out like she did with Lamar Odom.

This family sure sticks together.