While the image is captioned with three heart emojis, the siblings are photographed lying down and cuddling together.
Last month, the Celebrity Apprentice star, 34, shared a cute clip of her giggling baby boy.
On March 27, the businesswoman and her husband Jared Kushner welcomed their third child. She announced the happy news on social media.
“Jared and I feel incredibly blessed to announce the arrival of Theodore James Kushner,” she shared. “Baby Theodore. My heart is full. xx, Ivanka #grateful,” she later captioned an image with her baby boy.