Supermodels Gigi and Bella Hadid are opening up about discovering that they have a half-sister. The models said that their sibling, Aydan Nix, 23, was born of a brief relationship between their father, Mohamed Hadid, and a woman named Terri Hatfield Dull following Mohamed's divorce from their mother, Yolanda Hadid, in 2001. "Over 20 years ago, our dad, while single, had a brief relationship that led to a pregnancy," Gigi, 30, and Bella, 28, told the Daily Mail in a statement on Thursday, May 29. According to the sisters, Aydan was "born and raised in Florida, growing up with the man she lovingly knew as her father until his sudden passing when she was 19." Following her father's death, Aydan "decided to take a genetic test out of curiosity" and discovered her "biological connection" to Gigi and Bella. Model Moms! A Guide to Gigi, Gisele and More Supermodels' Kids The half-siblings "first connected in late 2023" and the Hadids have since "embraced Aydan with open arms," the statement said. (Us Weekly has reached out to Gigi and Bella's representatives for further comment.) In addition to Gigi and Bella, Mohamed, 76, shares a son, Anwar, 25, with Real Housewives of Beverly Hills alum Yolanda. He also shares two daughters, Marielle, 44, and Alana, 39, with his first wife, Mary Butler. Scroll down to learn about Aydan: Courtesy of Aydan Nix/Instagram Aydan Nix Lives in New York City The Hadid sisters' statement noted that Aydan and her family "value their privacy" and asked the public to "honor her wish and right to her anonymity as she continues her life as a young woman in New York." Aydan Nix Is Originally From Orlando, Florida According to the Daily Mail, Aydan was a cheerleader and honors student in her native Orlando, where her mom, Terri, works as a mortgage loan expert. While a student, Aydan worked a summer job at Domino's Pizza. Hollywood's Most Memorable Celebrity Siblings Over the Years Aydan Nix Recently Graduated From Parsons School of Design Like her sisters, Aydan appears to have her sights set on the fashion industry. She recently graduated from the Parsons School of Design in New York. Earlier this month, Aydan shared snaps from her graduation, which show her sporting a red gown and traditional graduation cap, via her public Instagram. "WTF.......... post grad ........," she captioned the post. View this post on Instagram Aydan Nix Is Getting to Know Her Family Gigi and Bella told the Daily Mail that Aydan has "spent time with all of us, including our dad, and we've cherished this unexpected and beautiful addition to our family." "As siblings, we've had many open and loving conversations- with Aydan included -about how to support and protect her," the statement added. Aydan Nix Has a Close Relationship With Her Mom To mark her mom Terri's 50th birthday in February 2023, Aydan shared a touching tribute to her mother via Instagram, writing, "She's the most beautiful person I've ever known and ever will know." "Sometimes I call her 4 times a day. She always answers the phone," Aydan wrote, noting that her mom is her "role model and my best friend." Why Gigi and Bella Hadid Waited to Introduce Aydan Nix to the World A source exclusively told Us Weekly in May 2025 that Gigi, Bella and Anwar had "been in touch" with Aydan for "about a year and a half" before they introduced their half-sister to the public. "They have welcomed her with open arms and are fully embracing her as their sibling," the insider added. "They kept this news a secret for the sake of Aydan's privacy. The Hadid sisters and Anwar have tried to not pass judgment about the situation." Though Gigi, Bella and Anwar had "a lot of questions" about the situation, the source said they remained "positive" and "open-minded." "The family wanted to keep things private until Aydan was ready. Gigi and Bella have given her space but are always warm and there for her if she wants to get in touch or see them," the insider continued. "They don't see each other often and haven't spent much time together. Aydan has a lot in common with Bella and Gigi and they have bonded over NYC and the fashion industry. She looks up to the girls a lot." Aydan Nix Details Her Relationship With Gigi and Bella Hadid Aydan detailed her bond with Gigi and Bella in a December 2025 essay for The Cut. "My sisters (along with the rest of the family) have been nothing but warm and generous. They have made space for me in ways they didn't have to," she wrote. "Anwar called me his baby sister the first time we ever spoke on the phone [and] Bella calls me her twin. ... My mom couldn't even tell our voices apart when we first spoke to her on the phone." Aydan continued, "Alana sent me resources and inspired me to become active in the fight for Palestine's freedom. I watched Anwar's film Walled Off. Gigi took me for my first Palestinian meal and taught me the names of different dishes." Aydan added that Gigi helped her break into the fashion industry. "Gigi introduced me to her friend, Gabri