"Happy birthday to our sweet princess, our little mermaid Penelope!!" Kris Jenner wrote alongside a photo collage of Penelope. "We love you so much, precious angel!! ❤ #HappyBirthdayPenelope #Angel #sweetgirl #family."
"Happy Birthday my sweet P! Thank you for being the best friend to my North! I love you!" Kim Kardashian wrote alongside a sweet photo of Penelope and her daughter, North, before sharing video of the girls' "party planning."