The "Keeping Up with the Kardashians" sisters rented a bounce house for the kids and and hired actors dressed as Moana characters Moana and Maui. Guests enjoyed barbecue ribs, macaroni and cheese, rainbow shaved ice and birthday cake.
The Kardashians were joined by brother Rob Kardashian and his daughter, Dream, and friends Larsa Pippen, Daphne Joy and Jaden Smith.
Pippen posted photos on Instagram of her daughter, Sophia, with North and Penelope.
"Working on those dance moves! Happy bday North," the former "The Real Housewives of Miami" star captioned one picture Monday.
"Cuteness runs in the fam! Happy bday Penelope," she added to another snapshot.
North celebrated her fourth birthday June 15, while Penelope turns five July 8. Kim and Kourtney previously marked North's birthday by dedicating sweet posts to the 4-year-old on social media.
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"Happy birthday to my mini me! I can't believe you are 4 already. I love you so much, Northie!" Kim wrote on her website.
"Happy Birthday to my Northie angel slumber party unicorn mermaid girl!" Kourtney added on Instagram.
Kim and Kanye also share 18-month-old son Saint, and hired a surrogate this month in an attempt to have a third child, according to E! News.
Kourtney is also mom to 7-year-old son Mason and 2-year-old son Reign.
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