She mimics him as he makes the gesture with his hand, although from the look on her face, she obviously has no idea what it's supposed to do. It isn't until he draws the line himself that her expression turns to one of surprise.

"Whoa! So it's like some kind of defensive spell?"

--Is apparently what she's getting out of this.

But hey, it's her turn now, so with all the confidence in the world, she turns and points at the ground, tracing a line through the air...