Really? Who would that be up to - Mattis, Trump?
I was lucky enough to have never run afoul of the UCMJ so I don't have a good understanding of how it works.But IMO this would qualify as "insubordination" which,I believe,is a violation of the UCMJ. That would mean that any superior officer in her chain of command would have the authority to refer charges against her.And that would start the court martial process.