The Dunedin lawyer had decided it was time to do something for the community in which she lived.
Not entirely sure what that would be, she was bothered by media reports on poverty and children going to school hungry.
But it was not until she read an article in the Otago Daily Times about dumpster diving - people retrieving food from skips - that she realised food rescue was what she wanted to do.
So she set up FoodShare, an organisation based in Dunedin that collects excess perishable food from donor businesses, and then sorts and distributes it to social service agencies and community organisations to pass on to those in need.
Since making the first collection in March, 2012, FoodShare has saved nearly 212,000kg of food from being dumped in the landfill and provided 605,000 meals.
Not only was it helping feed the hungry but it was also reducing food wastage.
The water saved through the initiative was the equivalent of nine Olympic swimming pools, while 55 New Zealand homes could be powered in a year with the energy that had not been wasted.
Now an equivalent service has been established in Auckland and Ms Manning, who is chief executive of FoodShare, could not be happier.
''You can't underestimate the feeling you get when you do something for someone else. You get hooked on it - it's very, very, very satisfying,'' she said.
Warm and engaging, with an obviously sharp business acumen, Ms Manning was brought up in Palmerston North, where she enjoyed a ''typical'' active childhood - ''barefeet, running around, climbing trees'' - and came to Dunedin as a tertiary student.
After graduating with a physiotherapy degree, she lived in Auckland and then England, before returning to Dunedin in 1993.
She returned to university and completed a law degree, working in law firms in the city before deciding to have a change of focus and leaving her job four years ago.
Passionate about making a difference in the community, she set about researching what food rescue was all about.
''It was one of those things, if you didn't do it, you're never going to know what you can do; whether you can make a difference,'' she said.
It took about six months to get up and running and she recalled making her first collection from Wishbone, at the end of its first day operating at Dunedin Hospital.
She took the box of food home and weighed and recorded it, as she knew she would have to keep good statistics to help when approaching funders.
As the amount of donated food grew, a friend began helping her.
The day her car was so full of bread that she could not see out the back of it, she took a photo of it and approached Southern Motor Court which provided her with a van.
But the crux came when she was offered a tonne of onions and she realised FoodShare was going to keep growing and she could no longer work from home.
Now operating from premises on the corner of Ward and Halsey Sts, there were about 100 FoodShare volunteers whose work included weighing and categorising all the food and then allocating it according to the needs of the various recipient agencies.
It had grown from providing the equivalent of 1000 meals in the first month to more than 30,000 meals a month.
The number of donors was now in the mid-30s, as was the number of agencies.
FoodShare did not call itself a charity. Rather, it was a social venture and a business that ran on business principles, with targets and measurable outcomes. Those outcomes were not measured in dollars but social outcomes.
It was more than just food rescue.
There was also an educational side.
People often did not know how to maximise and store food and cook with it, Ms Manning said.
Recipes and workshops were being developed, with an opportunity for agencies to bring clients in for a cooking demonstration.
Engagement was also important and that covered ''every single person in the community''.
Everyone could engage with FoodShare to help ''nourish our community'', whether it was as a volunteer, or financially, or from organisations getting in touch, saying they needed food, she said.
People needed to realise FoodShare was not like a foodbank, as the food it collected was perishable, rather than tinned or dried - that service was already being done very well in Dunedin- and no money changed hands, she said.
Fruit and vegetables were particularly sought-after and recipients included the major foodbanks in town, Women's Refuge, the emergency night shelter and smaller community agencies.
When it came to donors, Countdown supermarket, which was its biggest supplier, was a ''perfect example'' of a large organisation which had turned what was waste for it ''into something positive''.
FoodShare never referred to the donated food as waste - ''because it isn't, it's a meal for somebody'', Ms Manning said.
The quality of the food donated had to be seen to be believed and people also did not understand the volumes that would otherwise go to the landfill.
FoodShare had deliberately kept a low profile, as it had not wanted to promote more than what it could deliver, but it also could not grow without financial support, she said.
While it had enough volunteers at the moment, what it needed was financial support.
For every dollar invested in the organisation, it could deliver the equivalent of three meals, so financial investment produced ''incredibly good outcomes'', Ms Manning said.
Team-building exercises were held, called Cooking for a Cause, which were designed to create revenue for FoodShare.
A team would work with a professional chef in a commercial kitchen to prepare meals for those in need.
They also enjoyed a meal, cooked by the chef and created from rescued food, and left ''absolutely buzzing'', she said.
It was not so much about making a financial profit but FoodShare needed to become financially independent and not rely on the insecurity involved in grant funding.
The business had value to many stakeholders in the community, not just the organisations that received the food.
It was all about ''putting Dunedin firmly on the map for a community that's getting involved and making a difference''.
''It's a win-win every way you look at it,'' she said.
In the future, Ms Manning hoped to see FoodShare housed in a bespoke building outfitted for every aspect of the work it did.
That would include a warehouse, walk-in chiller and freezers and a commercial kitchen to run Cooking for a Cause and also workshops and education programmes, including for school children.
Kiwi Harvest, the similar initiative in Auckland, had now been running for three months and there was potential in other centres.
''We've nailed it here in Dunedin. We know what we're doing here and we've had really good buy-in here.
''All you have to do is look at the area you're in and just adjust it slightly. The hard work has been done,'' she said.
When it came to setting up FoodShare's board, Ms Manning deliberately set out to recruit people with the skills needed.
There was a chef, a businessman, a lawyer, an accountant and her and it had proven to be a ''really good mix''.
The board was chaired by her brother, high-profile businessman and former All Black captain David Kirk, who had been ''absolutely brilliant'', she said.
Ms Manning's husband, Patrick, a doctor, had been very supportive, while their three children were very proud of the work FoodShare did.
''It's just worked out very, very well. It's so nice to have your dream ... really come to fruition and be working well and seeing the results and benefits,'' she said.
The Golden Centre Mall is hosting a black tie event at the Dunedin Town Hall as a fundraiser for FoodShare, on November 14.
