She was usually beaten with a steel-capped boot, or a belt.
Sometimes, he would tell her to remove her playing shirt, stand with her back to him, and then he would whip her - for losing.
She was repeatedly called a 'whore' by her father. And when she lost the semi-final of Wimbledon in 2000, her father told her to find somewhere to sleep at the Wimbledon courts that night because he refused to let her sleep at the hotel where the family was staying.
It is incredibly brave of Dokic to break her silence. How she played, how she made it to number four in the world while playing under such pressure - win or your father will beat you - is unfathomable.
It raises so many questions.
Who knew what? She was a child star. She brought in the crowds. She was one of the brightest tennis stars that Australia had ever produced, but she lived in an extremely dark world.
Some of the beatings were in the changing rooms.
The belt would leave welts and cuts across her back. Who knew what? She's in a changing room, for goodness sake. If people didn't see the beatings, someone - at least one person - must have seen the aftermath of the damage inflicted on her young body.
Tennis Australia says without cooperation from those directly involved - in other words, Jelena and her father - they couldn't investigate what was going on.
Well, really? I can't tell you what a distressing read this is.
This went on for years, and no-one did anything. No-one stepped in.
Jelena, despite her brilliance, never captured the heart of the Australian public - mostly because of her father's behaviour. And she sure had her fair share of critics. Those who believed she was cold, and surly....of course, now we know why. Now we know what would happen if she lost.
Read her story and you'll see her in a very different light. What a brave young woman she was - and still is. Her book is called 'Unbreakable'.
Tennis Australia has some questions to answer, for sure - they knew, but did nothing to protect one of their child stars.
But it also serves as a warning not to judge a book by its cover. Jelena more often than not attracted the criticism of the Australian public and its commentators.....if only people had stopped to question why her behaviour at times was questionable. Why she reacted the way she did when she lost.
What a lonely world she must have lived. It's a tragic story of a young girl at the top of her game who contemplated suicide.
And a sport that benefited from her brilliance, but failed to protect her from a brutality that no-one, not least a child, should endure.