The 28-year-old model posted several sentimental photos taken with Marielle — who is the daughter of Mohamed Hadid and his first wife, Mary Butler — from throughout the years on social media to celebrate the interior designer's 43rd birthday.
In the first black-and-white snap she shared on her Instagram Story, a young Gigi poses alongside a teenage Marielle.
“Wishing the Happiest birthday and a year to my big sis, LEAD HADID,” Gigi wrote, using a nickname for her sister.
In a second photo, the two sisters walk side-by-side in high spirits, with Marielle appearing to laugh.
A final image shows Gigi as a little girl wearing a tiara as she smiles widely alongside Marielle, who wears a pink halter top. Gigi added text over that picture, writing that Marielle is a “caring, funny, creative, amazing sister/mama/friend.”
Mohamed was married to Butler, with whom he shares daughters Marielle and Alana Hadid, until their split in 1992. He then went on to marry model Yolanda Hadid in 1994, and they welcomed three children: Gigi, Bella Hadid and Anwar Hadid. Yolanda and Mohamed split in 2000.
Despite the age gap between siblings, the pair have remained close throughout the years. In July, Marielle even shared a shot of the two having fun at a Taylor Swift concert on her Instagram.
While Marielle has mainly kept her life out of the public eye, she has also been involved in fashion just like her siblings. She co-founded the sunglasses brand Hadid Eyewear with Alana.
Over the summer, Hadid also celebrated sister Alana’s milestone 40th birthday by sharing a photo of herself posing in a cream-colored dress with her two older sisters at Alana’s festive Beverly Hills bash. Marielle wore a shimmery white one-shoulder mini dress while the birthday girl opted for a light brown cutout dress.
“Celebrating our sister!” Gigi captioned the snap. “Toga party ????????????????.”
“My Grecian Goddess Dream 40th ????️????✨,” Alana wrote alongside photos and videos of her special day. “I feel so blessed and loved and cherished surrounded by my friends and family from all over the world.”