Here, Erica Hammel, 30, tells the story in her own words...
Passing my baby son, Wyatt, to my ex-husband Bobby, I could feel my heart breaking as it did at these drop-offs every week.
Wyatt, 11 months, screamed, trying to hurl his little body back towards me, but I had to walk away, stifling my own sobs.
Once I got to my car, I put my head in my hands and, as usual, I bawled.
I cried for the family I’d lost after Bobby had his stupid affair, I cried for Wyatt who I had to keep handing over in our shared custody agreement and I screamed in frustration about Bobby’s new girlfriend, Rachel Edwards, who smirked at me every time I saw her.
‘I hate thinking about her with Wyatt,’ I told my dad, Robert. ‘There’s just something about her that makes me uncomfortable.’
She was the woman my husband of two years had left me for so I hated her.
But it was more than that. Call it motherly instinct but I couldn’t let it lie. I did all I could to find out about her.
I tried to verify rumours I’d heard that she’d had her own three children removed.
I checked if she’d been to prison, and I even looked her up on the sex offenders’ register.
But nothing came up to prevent her being around my precious boy.
‘I have to trust Bobby will keep him safe,’ I told friends.
But on November 1, 2013 – a few months after we’d started sharing custody – my worst fears were realised when I got the most shocking phone call of my life.
‘Wyatt’s been rushed to hospital because he’s breathing funny,’ Bobby said.
Then he dropped another bombshell. He told me he’d been at work and he’d meet me at the hospital.
Rachel had been with Wyatt.
At the hospital, a nurse spoke to me.
‘We’re doing everything we can,’ she said. ‘Wyatt’s had a major brain bleed. It looks like a non-accidental trauma.’
Walking into his room, I stopped in horror.
My happy, smiley baby was unconscious and grey.
I just wanted to hold him, but he needed life-saving surgery and child protection services wanted to talk to me.
It had quickly come out that Rachel had been convicted twice for child abuse and the victims, like Wyatt, were sons of men she had been dating.
The last case had been in court only 10 days earlier and she’d been slapped with just probation and a fine.
‘What?’ I screamed.
My boy, whose injuries included a fractured skull and broken ribs, consistent with shaken baby syndrome, had been left alone with her.
This was beyond my worst nightmare.
‘You have to be okay,’ I prayed at Wyatt’s bedside after his surgery.
When I saw his legs move for the first time I knew he had fight in him. And slowly he began to fight more, until six days later he was off life support.
‘You’re a miracle,’ I told him, as his long rehab journey began.
Initially, Bobby stood by Rachel, and thankfully they were both banned from seeing Wyatt.
As it became clear Wyatt was severely mentally impaired, I started getting impatient for justice.
Every time he ate, he choked and gagged because of the brain damage.
And my boy, who had been learning new words and babbling away, now couldn’t speak.
I felt so angry this had been allowed to happen.
‘If I’d known her history, Wyatt would never have been allowed to stay with her,’ I raged.
Eventually, in February 2015, Rachel Edwards, 32, pleaded no contest to second-degree child abuse and was given a 33 month to 10-year jail sentence.
It made me sick, especially as I’ll need to speak at her parole hearing every year.
But I’ll do it. I’ll do anything to keep that monster behind bars.
I’ve also devoted my life to passing Wyatt’s Law.
With the help of so many new friends, we have drawn up a bill meaning anyone who has been convicted of child abuse will go on a public register in our state.
‘It could prevent another innocent family suffering like Wyatt and I have,’ I tell people.
We’re so close to getting it passed and I’m so proud of both this achievement and also of how far Wyatt, now six, has come.
He is eating by himself and he says a few words too.
He always lights up when he sees me or his grandad, which makes every day feel so worthwhile.
It’s still incredibly challenging looking after him as he has the mental age of a three-year-old, but we have been blessed with amazing services and education programs to help.
Bobby lost custody and visitation of Wyatt and has done nothing to get back into his life, which is sad.
But it’s also a huge relief.
Wyatt’s by my side where he should always have been and where I know he will be safe and loved