"I had to rebuild everything," she told the National Press Club on Wednesday.
"All I had ever known was the life I had before prison."
Seven years on, the now 35-year-old criminologist, social justice advocate, and founder of the charity Project Herself is working to change the justice system by supporting vulnerable women.
"No one is ever better off after having contact with our justice system, and it's a failure we should be ashamed of," she said.
"We fail victims, we fail children, we fail taxpayers, and we fail communities."
Community safety had been confused with and replaced by punishment, Ms Isaac said.
"Our politicians have ... turned justice into political theatre and a vote-buying strategy, rather than policy that keeps victims and communities truly safe," she said.
"Safety can only be ensured if we provide an opportunity for repair after harm has been caused."
Prisons were necessary, but in many cases they were not the answer, Ms Isaac said.
"Holding people to account does not have to equal punishment," she said.
"Women who cause harm to others need to be given the proper resources to ensure they don't continue to do harm."
Ms Isaacs said she once shared a cell with a woman imprisoned for driving on a suspended licence.
And as an advocate, she had talked with women who had been charged for stealing food to feed their children.
Such women often lost their jobs, their homes and custody of their children in the process, forcing them into poverty or a cycle of offending, she said.
The woman should have been held accountable for her actions through education, reflection of her behaviour and been given the resources to ensure she did not reoffend, Ms Isaac said.
"A much cheaper, relational and practical way of handling breaches of our social contract," she said.
"Stopping cycles of disadvantage and incarceration starts with supporting women to stay out of our justice system."
Ms Isaac was released from prison in 2019 after serving a two-year sentence.
Project Herself is a charity that helps women rebuild their lives after they have been released from prison.
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