Whistleblower is commonly understood to uncover illegal, criminal or otherwise punishable activity within the organization, that is being hidden. Thus the metaphor of "blowing the whistle" - as in, attracting attention to something untoward going on. However, just releasing secret documents which do not contain the proof of any specific criminal, or otherwise untoward, behavior is not "whistleblowing". For example, Manning released 251,287 US Diplomatic cables and 482,832 Army reports - unless you consider the whole US Diplomatic corps and US Army to be a criminal enterprises, this goes way beyond whistleblowing, as described above.
I mean do you understand what it is that she "leaked"? Her intentions were obviously good, she was blowing the whistle on the government committing war crimes, at her own expense, no benefit. She may have not gone through proper channels, but you can't even really expect to be protected by those systems anyway. A "leak" is generally done for some kind of personal benefit or simply to cause harm and has no noble intention. the information leaked did not put anyone in danger but did expose crimes committed by the military. She should never have been jailed in the first place, free her.
A 'whistleblower' has protections gained by following the correct procedure to identify improper/criminal behavior first. If those actions result in punishment you can bring a suit against the offending party.