Kourtney Kardashian threw 1-year-old daughter Penelope a huge birthday party on Sunday at the Jenner household in Calabasas.

Penelope turned 1 on July 8 but her family waited until the weekend to celebrate and according to Us Weekly, there were approximately 150 guests in attendance at her party. 

Of all the friends and family, one important member wasn't there to celebrate - Penelope's cousin North West. An insider said the 1-month old newborn daughter of Kim Kardashian "stayed in the house because she's too little to be around that many people." However, "She's doing great though!"

Kim and her boyfriend Kanye West, who recently stepped out in public with their baby girl, are living in the Jenner household until renovations are complete at their Bel Air estate.

While little details were given as to who else was at the birthday party aside from family members, details of what was there were posted online. On the day of the party, Kourtney, 34, tweeted "Balloon partyyyyy!!!!! Geronimoballoons," followed by "Major balloon party, that is! Geronimoballoons." She also uploaded pictures of her in a floral dress sitting in-between two gigantic balloons.

The Geronimo Balloons were "3 ft. balloons with handmade paper frill to match the party colors-light pinks, nude pink, rose and creams. Each balloon takes the equivalent helium of 30 regular size balloons. Prices for similar designs to the Kardashians' is $150 each," an insider told the magazine.

In addition to oversized balloons, it seems that there were pony rides for kids. Kris Jenner posted a picture on Instagram titled "Unicorn sighting," when really it was a horse with a feathered unicorn headband.

Rather than tweeting about the party, the other Kardashians promoted that night's episode 7 of Keeping Up With the Kardashians.

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