Nicole Kidman celebrated her first Mother's Day since her split from Keith Urban by focusing on her children. "To my beautiful girls, the greatest joy is being your mother," Kidman, 58, wrote via Instagram on Sunday, May 10, sharing sweet throwback photos of herself playing with Sunday Rose, 17, and Faith Margaret, whom she shares with Urban. "Happy Mother's Day to all the mothers in the world 🩷🩷🩷," Kidman concluded the post. In one photo, one of her daughters was seen on Kidman's back while the actress beamed at her other daughter.