"She couldn't not work here," says Oldfield.
Her father, Ashley, soon joined them from their home in Queenstown. Her parents do the early shift - her mother baking the scones and muffins, her father the sweet treats and sandwiches. "He came up just to help out for a year. They are still going," laughs Oldfield.
Meanwhile, her sister, Michelle Burrell, an able chef, has been working with her from day one.
"She's very good at developing new recipes and bakes the best brioche."
Oldfield's 18-year-old daughter will be on the job over the university holidays.
More than four years on, the Dulcie May Kitchen is a well established part of Mt Eden with its lavish home-baking made on the premises.
Oldfield has ridden the wave of television interest in food like everyone else in her industry. She was a guest judge on MasterChef New Zealand last year. "It was great exposure, massive for the shop."
She has now produced four recipe books and a recipe notebook.
"Because some of my books are sold internationally, we have people from the other side of the world, coming in saying: 'It's part of my trip here from Adelaide ... or San Francisco'."
The Dulcie May Kitchen is turning over about $600,000 a year, while the books bring in a further $50,000.
"Almost five years on, we know what products work. Our granola is massive and biscuits, gingernuts, peanut brownie, shortbread and chocolate chip [do well]."
Content with one store, Oldfield would like to do more in publishing. She has an Australian publisher, Hardie Grant, and HarperCollins in New Zealand. Hardie Grant has taken her books to America where she has had some success and she is planning to develop a larger presence in America and then Australia.
"I want to share her with the world," says Oldfield of her grandmother. She has had a mentor, Geoff Blackwell from the publisher PQ Blackwell since the beginning.
It was a trip to America with her parents that gave her the idea for the books and the food store.
"For me New York is the ultimate place that represents the relationship between family and food."
Increasingly, Oldfield is driven by telling other people's stories. She is food editor for The Gardens, a glossy magazine for Mt Eden, Newmarket and Parnell. She goes into homes and people cook for her.
Meanwhile, Oldfield is grateful her grandmother's legacy of helping others continues. "There's a uniqueness in having family support and expertise. They understand, they are on board, physically but emotionally as well. A lady came in unwell the other day and we gave her a two-serve macaroni cheese. My family were quite happy about this."
And no doubt her grandmother would have approved.
Top Tip
Be strong and honest with family in business discussions.
Best business achievement
Getting her Gran's Kitchen book in the window of the Anthropologie store in New York's Rockefeller Centre.