Sept. 22 (UPI) -- Bindi Irwin and her husband, Chandler Powell, say their unborn baby is a girl.
Irwin, 22, and Powell, 23, announced the sex of their unborn first child in an Instagram post Tuesday.
Irwin shared a photo of herself and Chandler posing with a tortoise at the Australia Zoo. Powell is seen holding a sonogram in one hand.
"Baby girl, you are our world. Our beautiful daughter is now about the same size as a hatchling Aldabra tortoise and is as healthy as can be. We can't wait for her arrival next year," Irwin captioned the post.
Powell and Irwin's brother, Robert Irwin, responded in the comments.
I love you and our daughter more than anything," Powell wrote.
"I can't wait to meet my niece!" Robert Irwin said.
Powell posted the same picture on his own account.
"Our little girl and my beautiful wife are my entire world. I'm so excited to meet our daughter when she's born next year and to see the incredibly person she will grow up to be," he said.
Irwin responded in the comments.
"Here's to the greatest new life chapter. Baby girl and I love you beyond description," she wrote.
Irwin and Powell announced in August that they are expecting their first child in 2021.
"Becoming a dad is the highlight of my life," Powell said at the time. "I cannot wait to embark on this new adventure and life chapter with my gorgeous wife, @bindisueirwin. Bee, you're going to be the most amazing mother."
The couple shared a photo of themselves holding a sonogram earlier this month.
"We can't wait to teach our little one about the importance of protecting our planet and the beauty of the wildlife and wild places we love so much. Thank you for your kindness and support on this magical journey," they said.
Irwin, the daughter of Terri Irwin and late Crocodile Hunter star Steve Irwin, married Powell at Australia Zoo in March. The couple had to change their wedding plans due to the coronavirus (COVID-19) pandemic.
Irwin, Terri Irwin and Robert Irwin star on the Animal Planet series Crikey! It's the Irwins.