She's no longer in office, and she has proven that she can't be trusted with classified information, so her clearance should be cancelled. That said -- she IS out of office. Even at the basic "Secret" level that I held when I was in the Army, access to all classified information was on a need to know basis. I have no idea how many Confidential and Secret documents passed through my hands in the year I was assigned to a guided missile unit (defending Washington, DC). Doesn't matter -- I didn't need to know what was in them, so I wasn't authorized to open them up and read them. Hillary has no reason now to be looking at anything classified so, clearance or not, nobody with a clearance should be giving her any classified anything.
Remember, that's what hung Petraeus (well, along with a bit of adultery): His paramour was a commissioned intelligence officer with a top secret clearance -- but she didn't happen to have any [official] need to know the stuff that was in the documents the General gave her.