She had to undergo multiple operations, News24 previously reported.
The accident left McCusker stripped of skin and muscle.
She was also in constant pain and could not sit, stand or lie in one position for a long time.
The Witness reported, in 2015, that she settled on a R10.4 million payout from the Road Accident Fund.
McCusker published a book, titled "Scarred - But Not For Life", in which she described the pain and trauma she endured because of the accident.
Details about the cause of death has not been shared.
We live in a world where facts and fiction get blurred