Correct me if I'm wrong, but I believe your character's shield is strapped to her forearm which is how she's able to draw her sword with her left hand. While drawing the sword the shield would be pressed up against her left side, so moving it to compensate for Sigurd's sidestep would be impossible at that time. It is indeed fairly easy to redirect kinetic force from the side, but I highly doubt you could divert the blade sufficiently in this disadvantaged scenario (sword is angled to the right, pressure coming in from the same direction) to push it from the left side of your characters body to the right and completely away from her. It would either hit the opposite side of her chest, or presumably her arm or shoulder. The sword isn't going to rebound backwards like hitting a brick wall with a hammer.

I'd have to let [@Drifting Pollen] review the events so far, as I can't accept my character's thrust being voided in this fashion.