The post has racked up 11,000 comments, including one that pointed out Bob Irwin’s noticeable absence.
“What about your grandfather? You know, your father’s father! He too was a good man, who I assume got the shaft,” one Facebook user wrote.
Bindi replied with a lengthy statement revealing a deep family rift and levelling accusations of neglect – and worse – at Bob.
“Thank you very much for your comment. I really wish that my entire family could spend time with Grace,” Bindi began, referring to her baby daughter, who was born in March this year.
“Unfortunately my grandfather Bob has shown no interest in spending time with me or my family. Publicly, he continues to claim that he wants to spend time with us while privately my entire life has been psychological abuse from him.”