Her durability and sheer bloody-mindedness make her exactly the sort of player you want on your team.
But these days, the former Steel co-captain plays for the opposition - and no doubt with the same singled-minded determination.
She famously phoned Steel coach Robyn Broughton after a narrow loss to the Northern Mystics in Invercargill in May 2008 and talked late into the night dissecting what went wrong.
Two years later, the 35-year-old is back.
But this time she is playing for the Mystics and plotting the downfall of her former side.
The teams meet at Stadium Southland tonight.
"From here on in, every game is a must-win for us if we are going to have any chance of making that top four," Coffin said.
"The Steel are in exactly the same position, which should make for a cracker of a game."
The Mystics were meant to be one of the big movers this year after a busy off-season luring the likes of Silver Ferns Maria Tutaia, Joline Henry and Larrissa Willcox and Jamaican defender Althea Byfield to the franchise.
But with just three wins from seven matches, the team's season is teetering.
Coffin said it was a cliche but she felt the Mystics were improving with each match.
A close loss to the Magic, New Zealand's best team, was disappointing but also something positive to build on.
"We do have some momentum.
While it was gut-wrenching to lose by three goals, we've learnt a bit more about ourselves and how we react under pressure.
Hopefully, that will put us in a better position heading into this game."
Coffin made her representative debut for King Country at the national championship in 1988 when she was just 14.
She missed a year when she was at Police College in 1994 but returned and was a regular in the Silver Ferns squad from 1997 to 2002.
Coffin hung up the bib at the end of the 2008 season when she took on a role as TVNZ's weekend sports presenter.
But the retirement proved shortlived.
The temptation of a spot in the Mystics squad lured her back to court.
"It is quite full-on," Coffin said.
"We are together five or six days a week.
But I knew it was going to be that way.
So it is just a matter of making sure I'm eating and sleeping whenever I can, basically.
And working and training in between."
Coffin is one of the few athletes who have made a smooth transition from sport to broadcasting.
She is an engaging interviewer and a welcome presence on the small screen.
Her role means she has to take a broader view than just the Mystics-Steel match tonight.
One of the hot topics of discussion in the media and around the watercooler is the perceived gap between the Australian franchises and their New Zealand opponents.
During the course of her job Coffin spoke to Yvonne Willering about the issue, and the former Silver Ferns coach floated the idea of reducing the size of the New Zealand teams to 10 players and having a development group of four to six players attached to each of the squads.
"I quite like the idea. If they are training alongside the franchises then at least they are getting some experience. But it is not until you get on court that you actually learn things."
Coffin said New Zealand was well behind Australia in terms of player development.
"The Aussies have had the institute of sport there and systems in place for years.
We are only just kind of coming into that era where we realise that we perhaps need to develop something like that.
"There has been bits and pieces here and there around the country but nothing like the AIS, which half their girls have been through.
"We've been on the back foot since then. But I've got no doubt we have talent. It is just a matter of development."
The ANZ Championship has helped expose New Zealand's relative lack of depth in comparison with Australia rather than enhance it, Coffin said.
