“There are many things that I’m not yet aware of,” she shared with 9news.com.au.

Although new to the chamber, the former charity executive steps into parliament as a pivotal figure in the Labor Party’s sweeping election success.

Following in the footsteps of first-term Dickson MP Ali France, Witty became the second female Labor candidate to unseat a party leader, defeating Australian Greens Leader Adam Bandt with 53 per cent to 47 per cent.

But until recently politics wasn’t on the cards for the 52-year-old – it wasn’t even her idea to run in the federal election.

”I ran with Labor in the last Yarra council election and I came second in that election,” she said.

“And then because I’d run such a great campaign there, I was asked to run for the federal seat.

“I just thought it’s a good experience, and then maybe see what happens.”

Held by Bandt since 2010, the inner-city electorate of Melbourne seemed like an impenetrable fortress for the major parties.

Labor party insiders were quick to warn the Nappy Collective chief executive that overcoming Bandt at the ballot would be a huge challenge.

It was a feat four candidates before her had failed at during Bandt’s 15-year grip on the seat.

But on the ground, Witty quietly noticed “a groundswell of people looking for an alternative” after voting Greens for three elections in a row. 

“It was almost the first day out, we were at Richmond Market and the conversations started there,” she said.

“I started to realise like, yeah, this is a real chance here, and that’s when we really gave it our best.”

After five days of counting post-election day, Witty had picked up a 5.7 per cent swing towards her in the primary vote.

Just days out from election day, Bandt told media he was confident the Greens were “within reach of winning seats right around the country”.

“People are realising we can’t keep voting for the same two parties and expecting a different result,” he said.

In a somewhat prophetic turn of events, the longstanding MP would call his Labor rival just a week later to concede the seat.

“I will say it was the second most awkward conversation I’ve ever had,” Witty said.

The Scoresby-bred charity boss graduated from a “uninteresting, middle-of-the-road school” with vague ambitions to “enjoy life”.

Over the next four decades, she pinballed between industries, owning a Subway restaurant, working corporate jobs in banking and insurance and helping to raise a pipeline of $110 million for community housing as a partnerships manager for Homes for Homes.

“I’ve said all my life and all my career, I’ve never known what I want to be when I grow up,” she said.

Most recently, she took on the chief executive role at The Nappy Collective, helping to revive the charity which provides free nappies to families in crisis.

But it was her most intimate role – as a foster mum of 10 years – that the 52-year-old credits for her entrance to parliament.

“I had a child in my care who was about 10 years old, stayed with me two years. Really shy, really quiet, kid. 

“One day I picked him up from school and he says to me, ‘Oh, Sarah, can I tell you a secret?’ 

“I’m not gonna tell you his secret because the secret that he told me was something that no child should ever have experienced and the only person I’ve ever told his secret to was his caseworker. 

“But from that moment on, I knew that every decision I made from then on and continued to make, I always have him in my mind when I can.”

As the final moving boxes are flattened at her new office in the heart of bustling Fitzroy, Witty is finally sure of her purpose.

“I just want to make sure that my office is looking after the most vulnerable in our community,” she said.

“Just to let people know that we, we’re here to help, and that if they need help to come to us.

“I think by doing that, everybody’s lifted up.”