Brooke Shields began her career as a model as a young girl, but she's proved that she still has what it takes.
In the first of three pictures, Shields laid on her front and put her toned legs on display.
The two remaining photos featured the star wearing the swimsuit while accompanied by white flowers. The third and final photo showed some skin, as one of the swimsuit's straps draped down over Shield's shoulder.
"A great friend and a dream collaborator," wrote the actress in the caption. "Thank you for believing in my vision and helping bring it to life."
She then gave credit for the photos to Christensen, 51, who wrote in the comments.
"What a great day this was," she said, adding a trio of red heart emojis.
Shields teased a collaboration with the model on Instagram last week, sharing another swimsuit pic.
This time, the star donned a yellow one-piece with white lettering for a day on the beach.
The model sat down in the sand and tossed her long, dark hair back as waves lapped back into the ocean.
"Working on something special with my friend @helenachristensen," read the caption. "You are incredible. Stay tuned - exciting things to share soon."
Over the weekend, Christensen shared several photos she took featuring Shields wearing the swimsuits.
"Capturing a person’s essence isn’t always so simple. You wish to reach through the complex, sometimes guarded layers to find the vulnerable, raw, yearning truth in their heart and mind," the former Victoria's Secret Angel wrote in the caption. "This beautiful woman is someone who has shown those qualities to my camera lens for years. I am grateful to have her, not only as an inspiring photography subject but also as a caring, smart, witty, honest friend."
Also teasing the collaboration, Christensen added: "And I’m excited to be a part of a personal project she’s been working hard on for a while now."
"I trust you, I respect you, I’m here for you, and I appreciate you. I thank you for your eye, your character and your belief," Shields wrote in the comments.