On the Screen Actors Guild Awards red carpet last night, Nicole Kidman revealed that keeping quiet about her and Keith Urban's new daughter, Faith Margaret, was one of the most difficult things she's ever had to do. Kidman wanted to tell everyone, but revealed last night that the couple chose to keep her a secret because "we just decided this was our thing together. It kind of just perpetuated itself [and] it protects her, and it protects everyone in the situation."

Faith Margaret was born on Dec. 28 to a surrogate in Nashville, but Urban and Kidman are the biological parents. Their daughter was named for the actress' late grandmother, Margaret, whom Kidman cites as a great inspiration.

On last night's red carpet, Urban proudly showed off a photo of his new baby on his iPhone, saying, "She just looks like her [Nicole], don't you think?" The country star continued, "Family is a sacred thing. I think everybody understands that."

As for their 2-year-old daughter, Sunday Rose, Kidman revealed, "She’s so into [Faith] and she’s crazy about her. We really wanted Sunday to have a sibling, you know, so now we’ve got Sunday and Faith Margaret … we’ve got our hands full! We’re really happy.”

"Right now [they] are into ‘Skip to My Lou.' We crank that out pretty regularly," proud dad Urban added.

As for being the only male in a house full of girls, Urban says, “I roll pretty good with it somehow. I don’t know why, I just do." As for when they start dating one day, will he still be so mellow? The 'Put You In A Song' singer laughed as he told Access Hollywood, “Well, yeah, mellow might not be my thing at that point!”