Is the state dept one of the agencies that determine the classification level? If so, then yes, she’s guilty!
I believe the director of the originating agency for the classified document is the only one that can change the classification. I would suppose their boss could also change it. That is my recollection - if the NSA originates it another agency head cannot change it - it remains forever an NSA document.
Classified information is serious business and it has busted more than a few careers in government and led to imprisonment for far less than what she is alleged to have done. Based on everything I have read from reputable sources (not the hyperbole) is is abundantly clear that there were hundreds of violations in this circumstance. The idea of our Secretary of State using a private server (you KNOW it was hacked) is pretty ridiculous and politics be damned the intelligence community will not be quiet if they don’t charge her.
Of all the allegations against the Clintons over the years preceding his first term this could be the one. Did not think so at first, but it looks bad and it’s getting worse.