The Academy Award winner, 53, marked the holiday on Sunday with a heartfelt post that featured a snapshot of herself holding a bouquet of roses that she received from her daughters' school.
"I was sent this from my daughters' school and it says it all...," wrote Kidman, who is mom to daughters Sunday Rose, 12, and Faith Margaret, 10. "To all our women out there – to our mums, our grandmothers, our sisters, our daughters, our aunts, our girlfriends – I am so deeply grateful to the women who raise other women, who laugh, and love, and grieve, and befriend, and care, and never, ever, ever give up."
"Happy #MothersDay, and particularly to my Mumma xxx," the star added.
Meanwhile, Urban, 53, shared a tribute to his wife, whom he wed in June 2006. "Happy Mother's Day to mothers EVERYWHERE!!!! Happy Mother's Day to Nicole Mary. Our girls are ALL love, color, kindness and compassion, curiosity, and so much more because YOU are all these things …..and so much more ❤️❤️❤️ We LOVE you!" the country star wrote on Twitter.
Recently, in February, the couple and their two little girls made a rare virtual appearance at the Golden Globes.
And months before, Kidman gave a glimpse at their home life in the November issue of Marie Claire Australia. "I've got an incredible life now," she said at the time.
"I actually have a very simple life, strangely enough," she added. "Everyone thinks it must be so complicated, but it's not. My creative life is off the charts, but my actual life with my husband and two daughters is quite simple."
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The Undoing actress previously recounted the moment she knew Urban was the one to PEOPLE in January 2019. "It was my [38th] birthday, and he stood outside with gardenias at 5 a.m. on my stoop in New York," she said. "That is when I went, 'This is the man I hope I get to marry.'"
"It was pretty intense," she explained, while detailing their motorcycle getaway to Woodstock, New York. "I believed by that point he was the love of my life. Maybe that's because I am deeply romantic, or I'm an actress, or I have strong faith as well, but I just believed, 'Oh, okay, here he is.' "
Kidman also shares daughter Isabella Jane, 28, and son Connor Antony, 26, with ex-husband Tom Cruise, 58, to whom she was married from 1990 to 2001.