Today's Savannah Guthrie and her family are searching for answers amid the disappearance of mom Nancy Guthrie, Pima County Sheriff Chris Nanos exclusively tells Us Weekly. "As you can imagine, this is tough on all of them," Nanos told Us on Monday, February 2, when asked how the family is holding up. "They're leaning on each other. They're very cooperative with us and everything we're doing. They're involved and engaged. It is tough, there's no doubt." Nanos noted that Savannah's sister, Annie Guthrie, was the last one to see their mother.