Anneke's friends and family see the irony in the relationship, and the couple are going to Sunday's final with the legendary first-five.
"It'll be a really memorable night, hopefully. One to remember for the rest of my life. A once-in-a-lifetime experience."
A self-confessed rugby fanatic, Anneke is proud to have been born on such an important day.
"I'm known amongst my friends as the rugby-head, so I guess I'm a bit of a fan. It's cool sharing the date but obviously it would have been better being able to see [the game]."
She has been to Eden Park for all the pool games, one quarter-final and the All Blacks' 20-6 semifinal win over the Wallabies.
Anneke and Ryan, now one of New Zealand's top amateur golfers, met at a party several years ago.
"It's funny, before we met, we heard a son of a famous All Black was at the same event," said Anneke.
"My friends were thinking it would be quite funny if we met. But it's definitely not the reason we're together now."
Her mother, Robyn Ryff, said Anneke's date of birth must have had something to do with her rugby-surrounded life.
"I think it's fate. There's just all these weird connections to rugby," said Mrs Ryff. "She hung on until after we had won the cup - it was quite a memorable night.
"It was all elation when we won, and then we got a baby girl as well."
The 1987 World Cup final meant she spent some of her labour alone, Mrs Ryff said.
"My husband and my obstetrician were ducking out to watch the match. They left me to it a couple of times."
Anneke's father, Mike, said he remembered watching part of the game in the hospital waiting rooms, something that had become a running joke in the family.
"I did duck out a couple of times. It was a very long labour ... I certainly saw the last part of the game."
Mr Ryff said Anneke had been rugby-mad almost since birth.
"Strangely she's been a rugby fanatic ever since, without a doubt. I think it was born into her."
