Shivering, shuddering, etc.

Do we have a tag for what Shana is doing in this post #16738? It's a common enough reaction that it probably needs one.

I think it's surprised.

Well, she's definitely surprised, but is that a good enough match? Not all surprised people shiver, and not all shivering people are surprised (though most that have visible jaggies /will/ be surprised).

There's trembling, but that one does look like surprised to me.