The couple share two daughters -- 8-year-old Sunday Rose and 5-year-old Faith Margaret -- which Urban admits has been a bit challenging for him.
"I have no reference for girls," he explained. "I grew up in a house of boys, so it's quite the learning curve."
Kidman said she's learned a lot from her daughters as well, and credits them with her ever-evolving fashion sense and getting her mom style back on point.
"I would go to the school to pick them up, and they'd be like, 'Please don't pick me up in sweatpants or jeans,'" Kidman recounted. "They're like, 'Can you just get dressed up and do your hair and put on makeup and wear heels?'"
"I haven't thought of that," she shared. "I am just getting through the day."
Recently, Kidman sat down with ET at a junket for Lion, where she dished on the film's message of "unconditional love" and what part her own experiences with motherhood played in helping her connect to her role. Check out the video below to hear more.