At Ellerslie in 2008, she was pinned under a horse named The Cosmob after it had a heart attack 400m into the 1600m race, died and collapsed on top of her.
She was lucky. One of the starting stalls crew spotted the incident out of the corner of his eye and the entire crew set out in the pick-up. When they got to the spot in the Ellerslie back straight they couldn't see Thornton under the horse, but knew she had to be there.
Fortunately there were enough of them to manhandle 550kg of dead-weight off the jockey.
"When they got me out I wasn't breathing and they couldn't find a pulse, but the ambulance staff managed to get me around," she says.
One of the first woman jockeys to ride in one of the world's toughest races, Ellerslie's Great Northern Steeplechase, she continued so far into one of her pregnancies that she was partially responsible for NZ Thoroughbred Racing changing its rules to stop the practice.
Thornton says she will race "as long as my body allows me".