More importantly:
Intelligence reports containing foreign troop strength and movements are always classified information. This is not something that is ever done retroactively. It is not something that is a judgement call. We don't like to let people know what we have and to the extent we have it. It takes decades for this information to become declassified, usually long after the methods of data gathering and the data itself has become obsolete.
When it comes to knowingly, it's not a matter of proving that she knew but should she have known. And she should have known, given her security clearance level and position, that foreign troop strength and movements was classified information.
She should also have known that her private server was not an authorized location. This is why she is banging the "no classified information" drum so loudly.