“She’s going to be OK, but surgery — out of all the things we were ready for, that was not one of them,” he told PEOPLE.

Robert also revealed their mother, Terri Irwin, 60, had skipped the gala to stay by Bindi’s side at the hospital. “She’s just come out the other side of endometriosis and now the appendix goes,” he said. “Health is so important — it really is.”

Despite the intense pain, Bindi had still planned to attend the gala.

“She came to Las Vegas and was ready to come to the gala, put on a brave face in a lot of discomfort and a lot of pain and said, ‘Nope, I’m just going to tough it out, I’m going to go for it,’” Robert shared.

“But the