Kelly Clarkson has put her family first amid ex-husband Brandon Blackstock's private cancer battle, with a source shedding light into how she's been coping. "Kelly's work schedule has been difficult over the last few months as she needed to take care of her kids," a source exclusively tells Us Weekly. "She needed the time off as her kids come first. It's terrible and sad." Clarkson, 43, and Blackstock shared daughter River Rose, 10, and son Remington, 8.