Ms Brennan received a standing ovation after delivering the Australia Day address in Sydney on Tuesday, travelling from her remote farm in central-west NSW to discuss the rise of her online social campaign Buy From The Bush.

Living on a sheep and cropping farm outside the town of Warren with husband Jack and their three children, Ms Brennan said she created the platform to support remote communities during times of intense drought.

"Rural communities are a treasure worth protecting," Ms Brennan said.

"Not for their contribution to GDP but for something much greater; their contribution to Australian identity and the Australian story."

The campaign which encourages people to buy from the bush to support drought-stricken communities began as an Instagram account from the Brennans' Warren kitchen table in October.

The hashtag has been used 64,000 times on Instagram, with more than 400,000 people following the campaign on social media.

In the first six weeks, $2.6 million worth of revenue was generated for featured businesses, while 25 rural jobs were created from increased sales and more than $320,000 was spent on postage at rural Australia Post outlets.

"Buy From The Bush is less about crisis relief and more about sustainable support for rural communities in the long term," she said.

"At a time when much is made of the divide between city and country, between the left and the right, between big business and small business, the strength of a united community, albeit an online community, has achieved real change.

"It has opened up conversations, it has lifted spirits, it has created jobs and it has undoubtedly saved businesses."

After growing up in Sydney, Ms Brennan moved to the country about 10 years ago to support her husband's dream of becoming a farmer.

"We experienced consecutive floods, rising debt levels, the impacts of severe mental illness and intense family stress," she said.

"I learned about physical isolation, loneliness and exhaustion. I witnessed hard work under extreme conditions.

"Through the lens of a city girl's eye I saw mateship, love, devotion and resilience in a way I had never seen it."

Ms Brennan emphasised the importance of creating connections between the city and country, particularly amid the bushfires crisis blighting NSW.

"People feel they have been ignored and now vindicated in the worst possible way," Ms Brennan said.

"But I think blame tends to isolate; it does not empower.

"To me, it's not what the Australian spirit calls us to do."

Australia needed to start telling a different story about the bush, Ms Brennan said, centred on curiosity, interest, pride and desire.

"We are a country of people who want to help each other," she said.

"What a triumph that is. That ordinary people can have extraordinary impact."

Australian Associated Press