Model Christie Brinkley attends Target + IMG's NYFW kickoff at The Park at Moynihan Station on September 6, 2016 in New York City. (Photo by Mike Coppola/Getty Images)
Christie Brinkley signs copies of "Timeless Beauty: Over 100 Tips, Secrets, and Shortcuts To Looking Great" at Barnes & Noble, 5th Avenue on November 10, 2015 in New York City. (Photo by Slaven Vlasic/Getty Images)
Model Christie Brinkley attends Target + IMG New York Fashion Week Kick-Off Event at The Park at Moynihan Station on Tuesday, September 6, 2016 in New York City. (Photo by Neilson Barnard/Getty Images for Target)
Christie Brinkley showed off her toned beach body on Instagram
Christie Brinkley covers the Sports Illustrated Swimsuit Issue in 1979
Christie Brinkley. Photo: Ben Hider/Invision/AP
Christie Brinkley with her daughters Sailor and Alexa Ray in the Sports Illustrated Swimsuit Issue 2017
Model Christie Brinkley attends the NYDJ 2016 Fit To Be Campaign Launch at Lord & Taylor on January 28, 2016 in New York City. (Photo by Ben Gabbe/Getty Images)
Model Christie Brinkley leaves her Tribeca hotel on December 01, 2016 in New York City. (Photo by Ray Tamarra/GC Images)
Model Christie Brinkley attends Target + IMG's NYFW kickoff at The Park at Moynihan Station on September 6, 2016 in New York City. (Photo by Mike Coppola/Getty Images)
It's no secret that Christie Brinkley clearly has access to the fountain of youth, while the rest of us still treat it as myth; but the supermodel mother-of-two showed age really is just a number as she got back into a bikini for the 2017 Sports Illustrated Swimsuit Issue.
Brinkley already has four coveted covers to her name from the '70s to '80s, but the latest images make her the oldest woman to grace the pages of the annual magazine.
Last year, 56-year-old Nicola Griffin appeared as part of the Swimsuits For All ad which garnered headlines around the world, but she was not actually commissioned as a model.
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Paying homage to her heyday as a swimsuit supermodel, she donned a black mesh cut-out swimsuit as she posed with her daughters Alexa Ray (31) and Sailor (19) on the beach.
She excitedly shared the sneak peek on Instagram and thanked the magazine for featuring her in the upcoming issue, the latest in a series of more inclusive photoshoots after plus-size model Ashley Graham became the first model of her size to feature in the magazine since its inception in 1964,
"Thank you Sports Illustrated for sending the powerful message that good things come in packages of every size and we do not come with an expiration date," Brinkley captioned the picture.
"Oh and my kids think I walk on water, so let's not mention the apple box concealed just under the surface."
Christie Brinkley covers the Sports Illustrated Swimsuit Issue in 1979
Alexa, whose father is singer Billy Joel, said the show was "a little bit of a reality TV moment".
"We all have our own style. And Sailor is kind of the young new little, perfect little, sporty little model. My mom is almost, I tease her, that she's ADD in terms of how much energy she has. She literally can't stop moving.
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"And I'm still new at this and I was just trying to maintain my focus."