Naming their manager in twitter complaint and then asking people to spam every node in the org chart from their manager up to Sundar. Yeah, that is going to get the results you want...
Being young, in your "dream job" and then being told "there’s someone waiting outside to collect your corp devices" without any real explanation. It's 100% HR + Managers fault that this situation has escalated to this.
If a future employer asks for a reference from Google she's screwed.
This whole "don't say anything bad about X, it will reflect badly on you" is how the Epsteins and Weinsteins of the world go undetected for years.
If what she says is true she should probably go to a lawyer and sue.
But the complaints here seem to be related to performance management. Getting a frustratingly low rating. Being told that they aren't doing enough work. For this sort of situation I'd expect the firing process to take months.
"CME for missing a meeting" is strange, but the good news is that manager calibration notes are stored in durable systems and in many locales people have the legal right to see them. So it'd be possible to see if this was actually the reason for a rating.
We'll see if more information comes out.
If a manager really wants you gone they can manufacture evidence and have you yanked quickly by constructing unobtainable and/or subjective PIP targets.
It'd also be extremely odd to be on a PIP after receiving a Consistently Meets Expectations rating. Only a subset of Needs Improvement ratings actually get PIPs. CME, by definition, means that you are doing your job sufficiently.
If a future employer checks and see she was asking people to go and harass her former managers and HR, it'd reflect pretty badly on her; I know I wouldn't want her in my team.
And as for what she can do, isn't wrongful termination illegal? Like she could instead open a civil case against Google