This week on "Face the Nation," Hanna Siegel, the niece of American Keith Siegel, who is being held hostage by Hamas, joins Margaret Brennan one day after Hamas released a "proof of life" video featuring her uncle. Plus, Senate Minority Leader Mitch McConnell says he stands by "everything" he said in the days and weeks after the Jan. 6 attack about former President Donald Trump's actions related to that day.