Actually she'd be the last thing Bernie would want to talk about, not because she's an embarrassment to the Dems but because he is debating as a Dem candidate and so the debate should be about his understanding and vision vs. Trump's, with her being irrelevant. In Trump's case, not even talking about her is a fantastic way to make her appear marginal, unimportant, and 'Yesterday's news,' but given his personality I don't see him letting the chance to take a few potshots at her go by.
I disagree with most of what Sanders has to say, but I respect him for being as straight-up as you can expect from a politician. His own party would keep his wilder ideas in check even if he was by some miracle elected, which is not the case with Hillary who has no ideas except the centralization of power to the exclusion of Constitutional checks and balances in her own corrupt partisan political machine, continuing and accelerating a trend we've seen for the past eight years with Obama's increasingly-misnamed Department of Justice.