Bindi Irwin paid tribute to her late father, Steve, on the 15th anniversary of his death.

To honor her father, the 23-year-old mother and conservationist shared a special message alongside two photos -- one of her 5-month-old daughter, Grace Warrior Irwin Powell, and the other a throwback image of herself and Steve.

"This sweetheart has been watching her 'Grandpa Crocodile' on the projector at our camp here on the Steve Irwin Wildlife Reserve," Irwin wrote about Grace in the caption of her Saturday post. "She lights up when she sees him on screen."

"I wish with all my heart that Dad could hug my beautiful girl," Irwin continued. "It's been 15 years since he passed away. I hold on to the thought that he's her guardian angel now, watching over the most special part of my life, Grace Warrior. ❤️"

Steve Irwin died on Sept. 4, 2006 after he was stabbed by a stingray barb off the coast of Australia. He was 44 years old.

To honor the wildlife expert on the anniversary of his death, Steve's son Robert, 17, also shared a throwback image with him, captioning his post simply with a heart.

The late "Crocodile Hunter" star's family continues to carry on his legacy through their conservation efforts and in their everyday life running the Australia Zoo.

Irwin and her husband, Chandler Powell, named their daughter Grace, who they welcomed on March 25, after Steve. Irwin previously explained that Grace's middle names, Warrior Irwin, are a tribute to Steve and "his legacy as the most incredible Wildlife Warrior." Grace was chosen in honor of Irwin's great-grandmother and Powell's late relatives.

During an interview before Grace's arrival, Irwin explained how she was going to teach her daughter about the late "Crocodile Hunter" star.

"It is so nice that we'll be able to introduce her to her grandfather through all of the documentaries," she told Entertainment Tonight. "It's really special."

"I think it's really special that as a family we get to remember him, honor him in absolutely everything that we do. ... And make sure that that legacy never, ever dies no matter what," Robert Irwin said.