We all have that friend who swears blind they'll be leaving the pub after one pint, but there they are, several hours later, surging through last orders and leading the charge towards a nightclub as well.

Jenny Gunn may just be cricket's equivalent. "I'm the world's worst retiree," she laughs.

Last year, she did call time on her formidable 15-year England career, but at the age of 34, her protestations that she's past it appear to be falling on deaf ears among her friends and team-mates, in all corners of the world. One more before you go? … oh go on then… twist my arm.

"Literally, my bag was packed for retirement before lockdown," Gunn tells ESPNcricinfo. "I went to Australia over the winter and didn't take any kit, but the team was short because people went back home for Christmas, so I ended up borrowing Alyssa Healy's stuff and playing as a batter every game, which was lovely. She's got a really nice bat, actually.

"And when I got home, I was planning to play in the Hundred this summer, and that was it. But then when lockdown hit, I just thought, 'no chance, that's me done.'"

Not so fast. In an impressive, and allegedly accidental, reverse-ferret, Gunn won't just be turning out at Edgbaston on Sunday in the inaugural final of the Rachael Heyhoe Flint Trophy, she'll be doing so for a new team, and in both a role and a format that she'd thought she'd left long behind her.

"I only thought I was signing up for a T20 competition!" she protests. "The 50-over thing came as a shock to me."

And it was good old-fashioned peer pressure that got her to this point, as Gunn allowed herself to be caught off-guard by her old England team-mate turned Northern Diamonds head coach, Dani Hazell - at a moment when cricket might, understandably, have been of a secondary consideration.

"I sent Dani a baby basket for the birth of her son, and she was like, 'oh, what are you doing, do you want to play cricket?'" And so it began…

"I didn't have a job at the time so I thought, 'why not?' But I also thought I was just going to be a batter. But then Dani said, 'nope, you're going to bowl' and I was like, 'oh great, that's just what you want to hear…'

"But I've just enjoyed my cricket. There's no pressure on me, I'm just trying to help as much as I can. We have fun and that's what it's about. And getting to the final is the icing on the cake."

As one of the inaugural Chance to Shine coaching ambassadors, Gunn has long been in her element in a mentoring role, and a full-time coaching job beckons when - or if - she finally leaves the field for good.

But with seven wickets at 22.14 and 140 runs at 46.67 in her campaign so far, Gunn's enduring excellence has secured a hands-on role in a Northern Diamonds squad that epitomises the merits of mixing youth with experience.

"I want to get into the coaching side, but it helps so much to go onto the field and, rather than just telling them, you can actually guide young players through it," she says.

ALSO READ: From a farmer's field to Edgbaston - Georgia Adams' stellar season

Nothing epitomised that attitude better than her tour de force against her old club, Lightning, at Grace Road earlier this month. Despite dislocating her finger during a typically doughty bowling spell of 2 for 45 in ten overs, Gunn still emerged at No. 8 in the batting order with her side in some strife at 106 for 6 chasing 227, and eased her team to a two-wicket victory with an unbeaten 50 from 72 balls.

"That was a weird game," she says. "Luckily they kept feeding my bottom hand, as my dislocated finger was the top hand. But I was also lucky to have the experience of Beth Langston at the other end: we just rotated the strike and were never really in danger.

"Take the wickets out of it, the runs were never an issue, and that's probably what the youngsters in our team will have learned. Just try and stay in the game as long as possible, and next time it could be you who finishes the game and walks off the field as the hero."

A glance at the tournament averages provides a misleading take on Diamonds' run to the final. Certainly there's no single contribution to match that of Southern Vipers' captain, Georgia Adams, whose haul of 420 runs in six innings has been instrumental in their unbeaten dominance of the South Group.

Gunn, however, sees it differently - a case of their performances being shared around the squad to create a team dynamic that will stand them in good stead on Sunday.

"Each game we've had a different matchwinner," she says. "That shows the strength of the side when it's not the same people performing every time.

"Ami Campbell got 43 against Loughborough to get us going, Beth Langston scored runs, Phoebe Graham came in at No. 10 and scored the winning runs. We bat all the way down, whereas I think the Vipers are a bit top-heavy, and perhaps have relied on the same people. So it should be interesting to see what happens."

And then there's the late-flowing form of the young Dutch player, Sterre Kalis, whose introduction to the tournament could hardly have been more traumatic. Three ducks in a row, including an unplayable grubber on a slow, low pitch at Liverpool, might have crushed lesser characters. But scores of 87 and 55 not out in her last two games at Headingley have ensured she'll head into the final with confidence renewed.

"There was another big appeal on 0 the other day, and we were all like 'oh no!'," says Gunn. "When your luck is down, it's horrifically down, but sometimes you just need to get one away, and once she'd done that, she was fine. She hits the ball in different areas, so she complements our order nicely and hopefully she's got another innings to come on Sunday."

Speaking to ESPNcricinfo ahead of the final, Adams stirred the pot with her claim that Vipers "deserved" to win the title with the way they've been playing this summer. It's a claim that appears to stoke Gunn's already flowing competitive juices.

"I can't believe she said that!" she retorts in faux-outrage. "Why? Because they won six? It's weird, on social media, all the talk is about the south, no-one cares about the north. Honestly, it's how it always is. People were saying without any England players, Diamonds would finish bottom. It's like they hate the north!"

Rant over, Gunn has a more tactical analysis of Adams' merits. "It's not as if she's just been getting 80s and 90s, she's got a 150, so she's really kicked on," she says. "But we've looked at the footage, and we're working on ways to shut her down, or get her out. Our plans are in place.

ALSO READ: 'I've had 14 years of people calling me a chucker' (2018)

"I don't want to sound arrogant, but we've got a very good bowling attack - good quick bowlers, good spin bowlers - and while she's been really good at putting the bad ball away, I'd like to think we'll build pressure to stop that bad ball coming as often."

Diamonds will be up against a challenging attack themselves, not least the Vipers' new-ball pairing of Tara Norris and Lauren Bell, a lanky 19-year-old whose extra bounce and prodigious swing has been inadvertently replicated on the harder indoor surfaces at Headingley, where the squad have had to train due to Yorkshire's autumnal weather.

But whatever occurs on Sunday, and in spite of her protestations, Gunn is simply grateful to be back on the field of play, this summer of all summers, and to be playing in honour of Heyhoe Flint, one of the game's most iconic female role-models, who sadly died in 2017, a few months before Gunn's generation reclaimed the title that she herself brought into being back in 1973.

"Rachael is one of the reasons we are here, playing cricket in a professional capacity," Gunn says. "That team who went before us, they were just crazy people who loved women's cricket and sport, and fought for women to be put on the map.

"It was such a shame she wasn't there at the final, but she was definitely smiling down on us at Lord's on that day. Her family were there to share the honour, she's still with us, and I'm so glad the tournament is named after her."

One of Heyhoe Flint's team-mates, however, remains as indomitable as ever. At the age of 79, the mighty Enid Bakewell can still be found turning her arm over in club matches when the mood takes her.

Gunn, however, is adamant that there's a limit to how far she intends to emulate this particular role model.

'No, I am definitely not going to be the next Enid!" she says. "God, she played for our seconds in Nottingham a few years ago, and I was like, 'how the hell…'. Still turning it square, and running between the wickets, yelling at the kids "c'mon!" and "stop!"

"She's one of a kind. I don't think she'll ever stop." The same could be said for someone else.

Andrew Miller is UK editor of ESPNcricinfo. He tweets at @miller_cricket