The 51-year-old Australian actress and 50-year-old singer delivered a sweet rendition of Urban's song "Female" Thursday in honor of International Day of the Girl.
Kidman shared a video of the moment on Instagram. She said the clip was filmed by her two daughters with Urban, 10-year-old Sunday and 7-year-old Faith.
"To honor International #DayoftheGirl - filmed by Sunday and Faith!!! @KeithUrban," the star captioned the post.
"Female" appears on Urban's most recent album Graffiti U, which debuted in April. He discussed the song's significance in an interview with The Boot in June.
"It just hit me, as a father of young girls," the star said. "As a father and also a husband, I recorded it for my wife as well as my daughters, and also for my mom and for all the women in my life."
"It's a song of hope, and of what we want for our girls and for all women. It was so important for me to have that message of there, and that's why I wanted to record the song," he added.
Kidman and Urban celebrated their 12th wedding anniversary in June. Urban marked the occasion by dedicating a post to the actress on Instagram.
"12 years of celestial synergized soul dancing," he wrote. "Happy anniversary Babygirl!!! I love you SO much."