She and Riki Kinnaird, who both grew up in Dunedin, gave up the corporate world in London in 2010 to own and operate the Duke of Marlborough Hotel in Russell, Bay of Islands, with their friends and fellow University of Otago graduates Anton and Bridget Haagh.
''Honestly, people thought we'd gone nuts. My parents were like, 'You want to do what?'' Ms Shirley recalled.
Looking back, it was a ''massive'' gamble - ''but we'd do it all again'', she said.
''The Duke'', as it is known, has been named as a finalist in three categories in Hospitality New Zealand's excellence awards - for best country hotel (which it won last year), best redeveloped hotel and best accommodation hotel.
The winners will be announced in Queenstown on September 26.
The opportunity to buy the Duke was spotted by Mr Haagh, who contacted friends in London. He and Mr Kinnaird had talked about being in business back in their university days.
After much ''soul-searching'', Mr Kinnaird and Ms Shirley gave up their jobs - she was HR manager for a large Spanish bank and he was chief executive of a telecommunications company - and returned to New Zealand for the challenge of ''turning around a sinking business''.
Mr and Mrs Haagh did the same, giving up their Auckland jobs and moving north.
Fast-forward three years, and the Duke has been restored to its former glory and the two couples are very excited to have been recognised in the hospitality awards.
Ms Shirley said they acknowledged at the start the project could ruin relationships and friendships, but they had all managed to find niches for themselves and it had ''all worked out''.
Their families have also grown - the Haaghs welcomed baby Tom three months ago, a brother for 5-year-old Stella - and Mr Kinnaird and Ms Shirley have a 6-month-old daughter, Amelia.
The Duke of Marlborough is steeped in history, dating back to 1827, when it was known as Johnny Johnston's Grog Shop.
Ex-convict Johnny Johnston bought the freehold site of the Duke and he quickly changed the name to the Duke of Marlborough. He gained the first liquor licence in New Zealand.
Many changes of ownership followed for the hotel, which Ms Shirley described as ''quite an icon'' for both Russell and the Bay of Islands.
The 25-bedroom hotel on the waterfront had an ''absolutely amazing outlook''. Both her husband and the Haaghs had both spent time there in the summer holidays and saw ''so much potential'' for the business.
Much effort and work had gone into redeveloping the hotel, including replacing the leaking 60-year-old roof.
Business was going well and they had gone from hosting 10 weddings a year to 30, she said.
They tried to keep the business ''quite fun and casual'' and both she and Mrs Haagh referred to themselves as ''The Duchess''.
''The standard is really high but we don't want to turn into a corporate hotel. Fun dining rather than fine dining.''
Being recognised in the hospitality awards was like ''external validation'' for their hard work, she said.
''We spend a lot of time talking about what we could do better and what we haven't done quite right.
''It's nice after three and a-half years to say we have done something right. This business is a success not just because we think it is,'' she said.
A key factor in the hotel's success had been the support from the community which had been ''just phenomenal''.
''We feel like we're the custodians. It's a pretty cool story ... we're just adding another chapter.
''We're only here for our time and then somebody else will hopefully take it up and make it even better.''
In the meantime, she said she is looking forward to donning ''the glad rags'' for the hospitality awards.
''There's no call for high heels up here in Russell,'' she said.
