Bindi Irwin is expecting a baby girl

Bindi shared a photo of herself and Chandler with a sonogram photo and a giant tortoise surrounded by flowers and wrote on Instagram: "Baby girl, you are our world. [heart emoji]

"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.(sic)"

And Chandler shared his excitement on his own Instagram account.

He wrote: "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 incredible person she will grow up to be [heart emoji]."

The conservationist - who is the daughter of late 'Crocodile Hunter' star Steve Irwin - announced her "Wildlife Warrior" was on the way last month.

She posted a photo of her and Chandler, 23, holding up a baby sized version of their Australia Zoo outfits and wrote on Instagram: "Baby Wildlife Warrior due 2021.

"Chandler and I are proud to announce that we're expecting! It's an honour to share this special moment in our lives with you. Though I'm still in my first trimester, we really want you to be part of our journey from the beginning of this new life chapter. We couldn't wait to share the news as this beautiful little being has become the most important part of our lives.

"Your support means the world to us. Please let me know your best advice and send good vibes & prayers to our little sweetheart. Love & light."

Responding to his wife's post, Chandler wrote: "You're going to be the best mother."