Kelly Clarkson opened up about how her daughter River, 6, and son Remington, 4, are handling the big changes that have come amid her split from Brandon Blackstock.“It’s just one day when you’re like, ‘Wow, this has forever changed,’ and it’s not just my heart [that] has changed. There’s other little hearts, too,” the “Miss Independent” singer, 38, told Extra on Monday, October 12, while discussing the season 19 premiere of The Voice with fellow judge Gwen Stefani.