Hawn, 76, posted a photo of herself and longtime partner Russell, 71, on Instagram Sunday, all dressed in prince and princess costumes alongside their granddaughter, Rani Rose.
"Happy 4th birthday our precious Rani Rose🌹You are the real queen!" Hawn wrote. "I'll take Lady in waiting everyday as long as the prince is always beside me! WE LOVE YOU!!! 💕💕💕💕🎂🎂🎂🎂."
Goldie Hawn Instagram
"Our dreamy girl is 4 years today! Happy Birthday to Rani Rose!" Hudson, 43, wrote on Instagram. "Rani fills our hearts so full of love as she meets everyday with enthusiasm, beauty and humor. We partied hard today… the princess way 👸🏼 #HAPPYBIRTHDAY."
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In addition to Kate's three children — she shares her oldest son Ryder, 18, with ex-husband Chris Robinson, and second son Bingham, 11, with ex-fiancé Matt Bellamy –– Hawn and Russell also have four other grandchildren: Oliver Hudson's sons Bodhi Hawn Hudson, 12, Wilder Brooks Hudson, 15, and daughter Rio Hudson, 9; and Wyatt Russell's son, Buddy Prine Russell, whom he welcomed last year.
The extended family has happily gathered for both red-carpet appearances and smaller celebrations at home over the years.
Last year, Hawn and Russell were surrounded by their grandkids as they supported Hudson during the 2021 Golden Globes, where she was nominated for best actress in a motion picture – comedy or musical.
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In a photo shoot for PEOPLE's Beautiful Issue in 2020, which featured Hawn and Hudson alongside Rani, the mother-daughter duo spoke of the multi-generational bond they share.
"When your daughter has a daughter, it's a big deal," Hawn said. "I mean, it really is."
Hudson herself added that she has relished the special bond she shares with her daughter after having two sons.
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In February, the Mother's Day star opened up about her and Rani's relationship, telling PEOPLE they enjoy spending time together in the kitchen.
"Rani loves food and I cook with her all the time. She's my little helper," Hudson shared, noting that Fujikawa, 36, often steps in as her sous-chef. "She's very precise in everything she does."