The crocodile hunter and conservationist died in September 2006 after being struck in the chest by a stingray while diving on the Great Barrier Reef.
His widow Terri and father Bob believe that the psychic contacted Irwin after flying to Australia to conduct a seance.
Bob said: "There's no doubt that Steve was with us. There was a definite Steve energy that's unmistakable."
Terri added: "John doesn't have all the answers but he gives beautiful glimpses that loved ones we've lost are doing well.
"I know Steve's gone but in some way he's still here. I feel him. I sense him. That's very nice and comforting."
She banned the couple's children Bindi, nine, and four-year-old Robert, from attending the seance in case they were "traumatised".
Edward, who rose to fame with TV show Crossing Over, later addressed a 4500-strong crowd at Irwin's Australia Zoo on the Sunshine Coast. However, Irwin did not make himself known at the event.
Terri told the audience: "If any of you are wondering why Steve didn't come through, it's because, look around you, he's everywhere."