Qualified doctor Holly said: "It makes me feel sick thinking back to the night of the fire.
"It was an experience I hope none of us have to ever go through again in our lives."
The 61-year-old British tycoon's son Sam, 25, rushed over to the property to help evacuate the guests - and feared his grandmother and sister had been burnt alive in the "horrific" accident.
He explained: "I woke up to a nightmare. The sight of our home was horrific - amidst the storm all I could see was a huge ball of flames and a giant orange glow reflecting off the rain.
"I thought everyone inside was being burnt alive. I couldn't believe my eyes. I ran barefoot over cacti, through the hurricane force winds.
"All I could think was I've got to try and save what was left of my family, and did my best not to break down."
Richard - who was staying in a villa 100 yards away from the fire with his wife Joan - praised Kate's actions after she rescued his mum.
The Branson family's pet tortoise ET has also been found alive and well in the ruins but has a charred shell.
- BANG! Showbiz