She was 24 years old when he punched her in the head while she washed the dishes at her Darwin home, after he became angry over a text message on her phone.
Ms Leong sustained a traumatic brain injury and now relies on others who saw what happened to explain events to her.
Her sister Lorrena Tyson was home at the time and said she "locked eyes" with Ms Leong as she fell to the ground "like dead weight".
'Out cold on the floor'
Their mother Kadeja James was driving home from work when she got a panicked call telling her Ms Leong was injured.
"I walked into the house and Myra was out cold on the floor," she said.
"Myra was coming in and out of it and I automatically knew that she had experienced some brain trauma."
The assault caused vessels in Ms Leong's head to bleed and the pressure caused her brain to swell and shift two millimetres.
She was placed in an induced coma for 11 days and underwent brain surgery.
Weeks were spent in hospital rehabilitation learning to walk and talk again.
"I had headaches all the time from the lighting and the sound and certain people's smells," Ms Leong said.
"It was just not a nice place to be and I didn't even know why I was there."
The long-term toll of domestic violence
Almost a year after the assault, the former maritime worker still struggles with debilitating headaches, fatigue and memory loss.
Doctors have not been able to tell her if she will ever make a full recovery.
"I suffer from mood swings, so I can just snap straight away, and then after it happens ... I realise, 'Oh no, that was me — but it wasn't — it's my brain injury'.
"I also have a really bad memory, so people have to constantly remind me when I have appointments or things and I have to write it in my diary with dates and times.
"Each morning I will refer to my diary."
Struggling to keep a job
She said that prior to her injury she could work 12-hour days out at sea, but now she struggles to hold down a job because of fatigue.
The injury has affected her earning capacity, and she has set up a crowdfunding page to help with her recovery.
"Half of my Centrelink payments I have to put on rent and then the other half goes on food and then my monthly phone bill, electricity, fuel from appointments, things like that," she said.
"I'm left with maybe $100 for the two-week period.
"It's extremely hard, it's frustrating, it stresses me out, it makes me upset, but I have to just keep pushing forward."
Ms Leong now has her doctor's permission to train again at her local gym, where she gets what she calls "the best therapy".
"You get rid of all your stress and frustration and anger and leave it there and you feel great after it," she said.
Ms Leong said she was in a violent relationship with her former partner for more than a year, could not find a way out, and became withdrawn.
Her family noticed her behaviour change and that she was becoming "more distant" but they were not aware the relationship was violent.
"Don't put up with that stuff because it's not right and you're just going to live a bad life," she said.
This article was written by Eleni Roussos and has been copied from here.