I see her union is supporting her.
I feel sorry for her at one level, since -- to my mind, at least -- she made a catastrophic error of judgement in choosing to retweet the piece, but what's descended on her head as a result is surely disproportionate.
On the other hand, I can see why the Washington Post are furious with her, though it might have been far better, and also far more humane, to put her on paid leave until the fuss dies down, with a strong recommendation she stays low for a few days and gets out of town for her own safety after the threats she's been receiving.
Then, when everyone has had a chance to take stock once the immediate furore has died down, they could tell her, if it then still seemed appropriate, that they wanted her resignation for dropping them in like that, without warning anyone.