The 27-year-old glamour model posted the image hours after boyfriend Rob Kardashian celebrated his 29th birthday at a St. Patrick's Day-themed party with his family.
"Girl bye," she wrote alongside her yearbook photo, which displays her real name—Angela White—and shows her sporting straight dark blond hair, a white choker and a black off-the-shoulder V-neck top. "Chubby face 17 years old."
Chyna, who often changes her hairstyle, was not spotted at Rob's party. The two, who stepped out as a couple in January, had celebrated his birthday together late last week, also at a St. Patrick's Day-themed party. Chyna's son King Cairo, 3, also attended.
While Rob was with his family, Chyna appeared to spend Saturday night with a girlfriend. She posted on her Snapchat videos showing the two driving.
Rob's sisters, including Kim Kardashian, 35, Kourtney Kardashian, 36, and Kylie Jenner, 18, posted photos and videos of his party on Instagram and Snapchat. Rob, who had up until a couple of months ago largely stayed away from the spotlight for a while, appears in his first public group family pics for the first time in years. Sister Khloe Kardashian, 31, is not pictured.
Other attendees included Kris Jenner, 60, Kim's husband Kanye West, 38, their daughter North West, 2, Kylie's boyfriend and King Cairo's father Tyga, 27, Kourtney's ex Scott Disick, 32, and their eldest child, son Mason Disick, 6.
"You are the most amazing man who is kind, funny, smart and you have the best heart," Kris wrote on her Instagram page to Rob. "You are beautiful inside and out and have brought so much joy into my life. I love you soooo much."
"FAMILIA," Kim wrote.