Christie Brinkley poses for Sports Illustrated swimsuit issue at 63

Feb. 7 (UPI) -- Christie Brinkley is returning to Sports Illustrated at age 63.

The supermodel, 31-year-old daughter Alexa Ray Joel and 18-year-old daughter Sailor Brinkley Cook, will appear in the magazine's forthcoming 2017 swimsuit issue.

"Yes! I am excited to announce that I am back in @si_swimsuit..I figured with my gorgeous daughters @alexarayjoel and @sailorbrinkleycook by my side whose going to be looking at me!" Brinkley captioned a photo of herself with Alexa and Sailor.

"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!" she added.

Brinkley was the first model to land three consecutive SI swimsuit issue covers -- 1979, 1980 and 1981 -- and has made several appearances in the issue since. She told People she agreed to do the new issue with her daughters' encouragement.

"My first thought was, 'At my age? No way!'" the star admitted. "When I turned 30, I was like, 'This is the last time I'm posing in a bathing suit!' When this issue comes out, I'll be 63. I thought, 'Those days are over.' But to get to do it with my girls, I thought, 'One last go!'"

"In a country that's very ageist, people love to put you in little boxes," she said. "Women feel very limited by their numbers. On a personal level, I thought, if I can pull this off, I think it will help redefine those numbers and remove some of the fear of aging."

Brinkley shares Alexa with second husband Billy Joel and Sailor with fourth husband Peter Cook. Sailor, an aspiring model, entreated fans in an Instagram post in August to stop comparing her to Brinkley.