It's entrenched in her bloodline, her family's been involved at league's coal face since its 1915 birth on "the coast".
She met her husband, Nick, when he went south for a clash between Coasters and the Ngongotaha club. Their sons have been avid players who, like their parents, have moved into coaching when their own offspring began to run with the ball.
But today it's Jenny the floodlights are shining on and she doesn't like it one bit.
"I just do what I do," is her muted response to our approach for an Our People profile.
Pointing out others disagree, she acquiesces but insists she's only doing so for the sake of league's profile, not her own self-aggrandisement. If there's one thing Jenny Nahu isn't it's a self promoter.
But were it not for Jenny's promotional and fundraising skills league in this region wouldn't be the force to be reckoned with it now is.
To quote from the citation that accompanied her Zonta nomination "her influence in league in the Bay of Plenty as been outstanding, giving 46 years' service to the sport at club, schoolboy and district board level".
By doing so she's taken it from its grassroots, when local playing fields were fragmented (the Medical Officers Reserve, Park Road and the Ngongotaha Domain) to its present Puketawhero Park site.
Now the Bay of Plenty's regional headquarters, it's regarded as one of the country's top playing venues.
Geographically, the BOP region's vast, incorporating Rotorua, Putaruru, Tokoroa, Mangakino, Turangi and Taupo. Jenny's its secretary/treasurer, a role she estimates occupies her a good 60 hours a week.
She insists tributes be paid to the other women on the BOP board, they outnumber the men five to three.
"They have jobs to do and do them well."
Jenny's been doing her's far better than well since she, Nick and three of her children put down roots in Nick's home town in 1967. Their fourth child was Rotorua-born.
Naturally they slipped straight into the league scene.
"People from Ngongotaha wanted Nick to play for them, he was a centre, fast and a New Zealand trialist."
When their own offspring began playing she found herself looking after "lots and lots of kids, I was coach, manager, team mum, team cook and laundry woman . . . washing playing gear's just another job that comes with the game, the boys made themselves at home at our place."
Supporting rep teams involved a lot of travel and that didn't come cheap.
"The men used to get pongas from the bush and build fences. It was the time when beer came in quart bottles and crates; we'd collect the empties; that brought in really good money, we catered for weddings . . . in those days clubs didn't get the funding they do today."
Bottle collections went into overdrive to raise the cash to get two teenage Ngongotaha teams trans-Tasman; the first played their Aussie counterparts from Brisbane to Sydney, the second covered the area from Townsville to Brisbane. Both ended at league's holy of holies the NRL grand finals in Sydney.
The Nahus were at Olympic Park a fortnight ago to see the Sydney Roosters trounce Manly Sea Eagles. Although the Cowboys are her NRL favourite she's a Sonny Bill Williams fan.
"It's not all about his body although it's very nice, but he's a really good player."
They'd accompanied the Ngongotaha Rugby League Chiefs team their son now coaches, before it set off to replicating the tour the Nahu seniors took in the 1980s.
Hard as it is to get Jenny away from her devotion to league, "it's the core of my life", we eventually manage to prise out of her that her feminine persona's not mired in the male-dominated sport.
She's an enthusiastic redecorator. "I'd change this place [home] every few months if I could" and much of her working life's been in fashion, spending more than 20 years behind Shanton's counter.
"It was great, a real part of the community, that's when there weren't a lot of other fashion shops around. I finished at 60, thinking I was going to get on with other things in my life."
Her heart was set on becoming a marriage celebrant.
"I guess I was inspired by all those weddings we catered for at Ngongotaha and we met a lot of brides in the shop," but when Jenny applied celebrants were in oversupply.
"I was invited to apply again but by then I was totally entrenched in rugby league."
