Coincidentally (no, not really), Hillary was being interviewed on Fox News at the time.

Via HuffPo:

Hillary Clinton revealed on Sunday that her mother, Dorothy Rodham, was a big fan of Fox News, the cable network that has devoted more than a fair bit of programming to critical coverage of her daughter.

“She was a big Fox viewer, I will tell you,” Clinton told Fox News’ Chris Wallace in her first post-convention interview.

Wallace, struck by the revelation, asked if Clinton was being serious.

“Yes, she was,” Clinton replied. “And she would get upset. I’ll be honest with you. She would get upset when some of the people you had on would say these terrible things about me. And that was when I was a senator running for president and for the first two years of being secretary of state. I would say, ‘Well, mom, if it upsets you so much, why do you keep watching?’ She said, ‘Well, I like some of the people and I have to know what the other ones are saying so I can understand and be against it.’”