On the eve of her 21st, Gigi shared throwback photos to her Instagram Stories as well as a photo of her holding newborn Bella.
"TOMORROW WILL BE 21 YEARS SINCE I MET MY FOREVER BESTIE @bellahadid ❤️ (me wearing all red on your actual day of birth is MAJOR and possibly the reason it's your favorite color 😜)," she captioned the adorable photo.
Bella commented below, writing: "OMG. I KNEW THERE WAS A REASON. LOVE U SISTER. !!!!! SO CUTE. 4EVER AND EVER. and ever. And ever and ever."
A few hours later, on Bella's actual birthday, Gigi shared even more old pictures of her and her younger sister.
"HAPPY 21st BIRTHDAY MY ANGELIC SISTER @BELLAHADID !!! 🍼💕 There are no words for how much I love you. You know I've been trying to protect u from the world since day one, 🤣 and 21 years later u comfort and inspire me more than you'll ever know," the model wrote.
"You have always marched to your own drum, and you make me so so proud. You are loving, kind, driven, perseverant, and forever cool af. 👑 You have a power to empathize with everyone & love always, and you make so many people happy in doing so! 🦋 So excited to celebrate tonight - Cheers to YOU Bella Kai Kai ⚡️⚡️🍸 I LOVE U MY LIL SISSYPOP"
Too cute. Happy 21st Bella!