The first thing Mrs O'Neil did at their new home was set to work on a large garden so she could grow food for the family.
"Fresh food is the best, but also spending time in the garden is good and healthy. Watching a seedling unfurl is pretty special. I also love sharing that knowledge, because so many people have lost sight of where their food comes from."
Mrs O'Neil began writing a blog about her gardening adventures. Through that she took part in a growing challenge run by gardening company Yates. She won the second one she took part in. "I had 138,000 words and just couldn't stop writing - I loved it so much."
Mrs O'Neil approached Yates to see if anything could be made of the blog, and their publisher, Harper Collins, offered a book contract immediately.
"It was amazing. You just don't get a book contract that quickly."
The Good Life: Four Glorious Seasons In My Country Garden was published in 2013 followed by a children's gardening book, Play in the Garden .
Now Mrs O'Neil divides her time between gardening and writing - she writes a column for the New Zealand Herald, Go Gardening, plus several parenting magazines and websites.
"I was never into gardening and I was never into writing, but now I love both."
At Whanganui Literary Festival, Mrs O'Neil will "share the craziness" that happened when her family moved to the country.
"Eight years later, our farmer neighbours still laugh at us."
Mrs O'Neil left Wanganui in 1998 to study, but she is a regular visitor to her home town, as her parents and sister all still live here. "It's always home, and it was a fabulous place to grow up."
* High Tea and Gumboots with Sarah O'Neil is on September 20 at 3pm in the Pioneer Room at the Wanganui War Memorial Centre.