"I started modelling again three years ago after a 20 year break and this was the first time I had modelled lingerie."
Despite sharing the catwalk with the likes of Helena Christensen and Naomi Campbell in the 80s and 90s, it was only recently Brewer decided to put herself out there and take more risks.
"When I modelled previously I missed a lot of opportunities because I was overly cautious and was always worried it would be a disaster," Brewer said.
"I'll be 57 next week and this opportunity came up and I thought, you know what, I just have to do it."
"It's been said before, it's the things you don't do that you regret at the end of your life, so I dived in."
Feedback on the campaign has been overwhelmingly positive and Brewer said she was proud to be part of something that challenged ageing and body image.
"Everyone likes looking at beautiful pictures but you have to realise all of the touched up images and all the perfection is really damaging."
"These are very real images which sends a good message I think."
Brewer said the shoot, by photographer Harry Were at historic Alberton House in Auckland, was "like a situation comedy."
"The house was open to the public that day and people were wandering about and I was lying around in my underwear so I felt like a bit of a sideshow," Brewer said.
"It was really quite funny, we all laughed about it and it ended up lightening the whole thing up."
Brewer, who is Scottish, but has lived in New Zealand with her husband and two daughters for 14 years, started modelling again by chance.
She was spotted on the street by stylist Karen Inderbitzen-Waller who introduced her to Unique Model Management which signed her on the spot.
Lonely co-founder and designer Helene Morris said the campaign was meant to challenge messages about ageing.
"The beauty and fashion industries are so obsessed with youth, but the reality is we are all ageing, and there are so many wonderful things about growing older," she said.
"So often the primary message around age is intervention, which is a frustrating response to such a natural, inevitable process."
Morris said Brewer was a natural fit for the brand, which aims to celebrate women who aren't often seen in mainstream media.