The 39-year-old actress shared a sweet moment with Hawn on Thursday during their family vacation in Greece.
The picture shows Hudson, the daughter of Hawn and Bill Hudson, putting an arm around her mom. Hudson, who is expecting a daughter with boyfriend Danny Fujikawa, also cradles her baby bump.
"Mama love," she captioned the post, adding a heart emoji. "@officialgoldiehawn."
Hudson is vacationing with Hawn and her longtime partner, Kurt Russell, brother Oliver Hudson, half-brother Wyatt Russell and 14-year-old son Ryder Robinson. Hudson and Hawn shared additional snapshots while celebrating Father's Day Sunday.
"For me... no one tops these dads," Hudson captioned a photo of Russell and Oliver. "I know there's a lot of people out there who feel the same way about their family. As it should be! So happy Father's Day to all the best dads in the world! #Pa @theoliverhudson #HappyFathersDay."
"Here's to the best daddy and GRAND daddy!! Xxx," Hawn captioned a picture with Russell. "Happy Father's Day to all."
Hudson is parent to Ryder and 6-year-old son Bingham Bellamy. She announced in April she's expecting with Fujikawa, and showed off her bare baby bump in a snapshot the next month.