Fans and friends flooded the comments with congratulatory messages, including Teresa Palmer who wrote, “Oh she’s just gorgeous, so much like you Megs xx.”
Celebrity stylist Lana Wilkinson also commented, “Congratulations Mum & Dad ❤️ you did it! Well done Rosie, big school girl now.”
"Oh she’s cute," wrote a fan, "bit of a mix of both of you has dads eyes the rest is you."
Megan, 47, and her fiancé Shaun Hampson, 34, are parents to both Rosie and 8-year-old brother River.
In 2019, the model spoke to Australian Women's Weekly about her daughter's unique quirks and characteristics.
"She's like a cross between a wrecking ball and a koala," laughs Megan. "She's cheeky, fearless, determined, and just a firecracker."
However, she also revealed Rosie can be "insanely shy" around unfamiliar faces.
As for son River, the mum-of-two explained how he differs from his sister with his more "inquisitive" nature.
"He's a pretty quirky, pretty cool kid," Megan told the publication. "He feels very deeply. He's very emotional, and he speaks his emotions, which I've always taught him to do."