Steve Irwin's children, 22-year-old Bindi and 17-year-old Robert, continue to honor him during meaningful moments in their lives. On Tuesday, Robert shared a smiling picture of himself on Instagram next to his late father's truck, and shared the very special first ride he took in it by himself after passing his driver's license test.Robert said he chose to take the car on his «first solo drive» to visit his newborn niece, Grace Warrior Irwin Powell.