"Our beautiful boy, Oscar Hamilton Stefanovic 💙 3.4kg, deep blue eyes and perfectly healthy. He’s absolute magic. 💫," she wrote.
After welcoming their second child, Henry, in 2021, Sylvia and Peter continue to share Oscar's adorable moments as an older brother.
For his second birthday, Sylvia made a homemade racetrack cake with an Australian Women's Weekly recipe and got friends and family together at Sydney Park for the festivities. Sharing a slew of pictures from the big day, including a family portrait with the cakes, the besotted mother wrote a sweet caption to mark the successful day.
"Cars on a cake and cuddles with mates…Oscar had the best time at his party. A fun little afternoon celebrating our sweet boy's 2nd birthday. 🎂 🚗 🤗," she wrote.
Sharing her "gratitude for the baby boys who landed in my arms" on Instagram, Sylvia has even joked that her children have grown so fast you "can't tell who's the oldest".
If there's one thing for certain, however, the parents are enjoying every moment of parenthood.