It's McCarthy's fourth day on the job when the Chronicle visits and she's excited about the new challenge.
McCarthy has moved from a 15-and-a-half-year banking career and says there's lots to learn "but it's still customer service here".
She is doing the business' accounts and currently learning the ropes in the shop after recently leaving her job with BNZ.
They are slowly making changes and increasing the range of products with the aim of becoming more of a mini-supermarket and local convenience store.
"We're bringing in more items people want and fresh produce and food to go is a big part of that," Cockburn said.
"We get a lot of tradies and reps who travel on the main road coming in.
"My background has been grocery and I've been working on everything but, so I'm chomping at the bit to get in there."
There was a perception that Four Square stores were expensive but that was not the case, with some items on special for less than the major supermarkets were charging.
"We're working hard to make sure our prices are at a level that people are happy to call in and use us as a top-up shop," Cockburn said.
"We want to get our ranging right so we welcome any feedback from customers on what they want."
When they took over, the couple kept two of the store's existing staff and have since employed seven more staff.
"Our focus is very much on customer service," Cockburn said.
"We want to go back to grassroots and have a very customer-focused store. It's number one and top of mind for all of us. We don't always get it right but we try to."
Those customers' wishes are to the fore as Cockburn makes changes on the popular icecream counter.
"I had to get rid of the chocolate dipper but we're working on getting a better option for chocolate dips which we'll have before summer," he said.
He and McCarthy say they need more practice on icecream rolling before summer hits, when the pressure's on with queues of customers watching the process.
"There's quite an art to icecream making," McCarthy said.
"You'll have three people standing at the counter watching you roll them and it's winter - it's not even icecream weather."
Once they have settled in, Cockburn and McCarthy plan to get involved in community sponsorship.
"We'd like to get into kids' sports sponsorship," Cockburn said.
"We go past Springvale Park and it's great to see kids out doing stuff in the fresh air rather than sitting behind a tablet or TV screen."
