But the gesture was a mistake, because it gave her a window to act, where she didn’t need to shield [him].  I didn’t even see her palm the knife, and her entire body moved with the throwing motion.

She was already readying to throw again.  Two knives at once?

[Edited] I badly underestimated how good she was.  The first knife hit the window frame a quarter-foot in front of [the target's face].

...

She’d pretended to throw two at once, but had held back the other.  Before [the target] fully processed the fact that [he'd] almost swung right into the knife’s path, she was throwing it in a simple clean, crisp motion.  No choreographing, no putting her entire body into the throw.  The sort of thing I could very nearly miss if I wasn’t paying enough attention.

Wildbow, Twig, 1.9