Because a decade and a half after Steve Irwin passed, she's still celebrating his marriage to her mom Terri Irwin.
"Soulmates," Bindi, 22, tweeted on June 4 alongside a throwback photo of the couple. "Happy Anniversary to my sweetheart parents. Your love is the stuff of miracles."
Terri, who wed the late Crocodile Hunter in 1992, seemed truly touched by her firstborn's words. "Thank you @BindiIrwin," she replied. "Today marks 29 years since I married your dad. He was a lot of amazing things, but most of all he was fun. Really, truly fun!"
Bindi's brother Robert Irwin, 17, also paid tribute to his mother and father. "Happy anniversary, Mum and Dad," he wrote alongside an old photo of Steve with a broken foot being pushed in a wheelbarrow by Terri. "(This is my favourite photo ever)."
Twelve years after Steve's heart was struck by a stingray's barb, Terri told People in a 2018 interview that she hadn't gone on any dates since his death.
"I think it's wonderful when people who have lost someone find love again," she said, "but I'm not personally looking, and I haven't been on a date in 27 years."
The conservationist added she's "content" in life. "I have two beautiful kids, a really full plate," Terri continued. "I've already had my happily ever after."
"Love is not a big enough word," Terri tweeted alongside the birth announcement. "My heart is so incredibly happy. And I know that Steve would be beyond proud. Grace is the next generation to continue his mission and message of conservation. She chose her parents wisely. Bindi and Chandler are already the best parents ever!"