Kimora Lee Simmons showed off her growing baby bump with a beautiful Instagram photo this week.

The model-turned-fashion designer posed on a yacht with the sunset behind her, while on a family vacation in the Caribbean.

"Sunset Silhouette... #StBarths #BigOleBelly," she wrote as the caption.

 Sunset Silhouette... #StBarths #BigOleBelly

A photo posted by Kimora Lee Simmons (@officialkimora) on Dec 12, 2014 at 1:36pm PST

This is the first personal photo the 39-year-old shared with fans to show off her baby bump. Yet, paparazzi snapped photos of the mother of three earlier this week and confirmed that she's expecting baby No. 4, two months after rumors circulated.

"She is not doing much," a source told E! News about Kimora during her latest pregnancy. "Eating, sleeping, enjoying family time."

Simmons is expecting her first child with husband and businessman Tim Leissner, whom she wed earlier this year. The star's famous first husband, Russell Simmons, was the one who announced the news of their marriage via social media and expressed nothing but kind words for the new addition to the family.

"All of us love @OfficialKimora but the fact is she is happily married," the business mogul tweeted in February. "Tim has been in the family for a while now."

The former couple divorced in 2009 after more than ten years of marriage. They have two daughters together - Ming, 14, and Aoki, 12. Simmons also has a 5-year-old son, Kenzo, with Guardians of the Galaxy actor Djimon Hounsou.