The Kardashian clan's teeny-tiny new addition is already a big star!
Friends and family took to Twitter to congratulate the proud parents—whose 2-year-old son, Mason, is no doubt ecstatic to now be a big brother—and to send their well-wishes.
"Welcome to the world, Penelope Scotland Disick!" wrote Kim Kardashian on her blog. "Kourtney gave birth to a beautiful baby daughter on Sunday and the whole family is so thrilled to finally meet her! She is absolutely perfect!"
The proud new aunt also copped to her big plans for her niece. "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."
Khloé later took to her blog to continue the gushfest:
"I'm an auntie again!" she wrote. "As I'm sure you all know, my beautiful big sister gave birth yesterday to the most perfect baby girl you've EVER seen—Penelope Scotland Disick! 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."