'They're not coming into our street just to have a stickybeak,' she said defiantly - 'stickybeak' being Australian for poking your nose into other people's business.
In this street alone, four houses were destroyed and many others damaged. The suburb, Elanora Heights, a quiet middle-class address with spectacular bushland and ocean views, was one of many hit by bushfires which laid siege to Australia's largest city for several days.
Being at the suburb's edge, a position prized for its views and facilities, left Bungoona Avenue defenceless when two terrifying firestorms engulfed the area in a scissor movement from the north and south last Saturday afternoon.
Bushland in all directions was left blackened and leafless. Sightseers began arriving even while the tree stumps still smouldered. Shocked residents were disturbed by carloads of people driving by at two o'clock in the morning, and feared a repeat of the aftermath of similar fires in 1979, when their short dead-end street was plagued by traffic for weeks.
So Joanne and her friends built a makeshift barricade, past which they would allow only residents' vehicles, relatives and friends, and essential services. It may not have been legal, but at least it left the fire victims in peace to try to reconstruct their lives.
At No 28, Jim Lavarack, a retired computer systems engineer, and his daughter, Louise, were in good spirits, although their attempts to salvage personal items from the twisted wreckage of their home yielded only a tiny vase and a ceramic bird.
Mr Lavarack, 70, had gone to help neighbours at the other end of the street when the fire began, and returned to find his own home in flames. By then firemen had arrived, but when he asked for help he was told: 'Sorry, mate, we've just emptied our last tank.'
Mr Lavarack has already decided to rebuild - with better fire precautions - the house among the trees that he and his wife, Suzanne, bought just two years ago. 'We picked it because of the bushland, the birds and the people here. It's a fantastic street to live in,' he says.
Wild birds had landed on their balcony every day and their native garden flourished, despite the poor, sandy soil. This week, after the fires, a 'catatonic lorikeet' visited the same balcony railing, now charred.
On Sunday, the couple had 'calamitous thoughts' about their home, and Mrs Lavarack could not face the thought of returning. 'But then she thought about it, and she said, 'You know, that street's full of love,' ' Mr Lavarack says. 'And that decided it.'
Insurance would cover most of the cost of rebuilding, and friends had offered alternative accommodation while the work took place. At worst, the couple would take a holiday in their camper van for a while.
'In fact, now I'm quite enjoying myself,' Mr Lavarack says. 'It is exhilarating in a way. I'm planning the garden already.'
Next door at No 26, Charles and Lynne Hill were also getting on with their lives, despite losing their home and most of its contents. Mr Hill had driven his wife and the family pets to safety, but returned to help neighbours, against police instructions. It was so hot that all he could do was stand on the other side of the street and watch his house burn down.
The couple's priority was finding a home to rent, after a poor start to the day in which their attempts to have breakfast were thwarted by a lack of power at the hotel.
The Hills were busy sorting through the remains of the home they built 19 years ago in an area where today prices often top Adollars 400,000 ( pounds 180,000). Their split-level home, with its four bedrooms, two bathrooms, rumpus room and swimming pool, was now wreckage.
Photographs, pets and important documents had been saved before the fire. Afterwards, the only thing recovered from the ruins was a bent and blackened candlestick.
But little things loom large at such times. Mrs Hill, a librarian at Sydney's Macquarie University, had helped to cater for another neighbour's engagement party on Saturday. The celebration was abandoned when the fires struck, and afterwards the neighbour handed out food amid the wreckage of the street.
'I was very pleased yesterday when they came over and said, 'Here's your salad bowl back,' ' Mrs Hill said. That doubled the family's tally of possessions from the house.
'There may be more things under the bricks, but we'll probably have to put the bulldozers through the place this week,' said Mr Hill, a manager with the Department of Planning.
The couple were more thankful for their lives, and for the fact that all their children were away at the time of the fire. The youngest, Andrew, an actor in the television soap Home and Away, was in Britain; their middle child, Justine, is backpacking around Europe; and their elder daughter, Cassandra, had moved out only a week before.
Meanwhile, at No 32, Mark Williams was coming to terms with the destruction of his parents' home. He had just completed the four-hour drive from Canberra after seeing the house in flames on television there.
He said his parents, Helen and Tony, were staying with friends nearby and were 'taking it pretty hard'. They had been working for months to prepare their home of 15 years for sale. Their plan was to build a retirement home on land they own on the coast.
'I'm not sure what they'll do now,' he said.