The punching motion of drawing her sword from the front of her waist, (still protecting her chest, I just tested this with my own shield and sheathed sword.) whilst thrusting her shield in front of Sigurd's sword is simple. Gladius are short-swords meant for extremely close quarters combat. She'd angle the sheath sideways during the motion. And I must repeat... her left shoulder was facing Sigurd, her right shoulder was not. Her stance shifted. Even if the shield had been turned sideways, it would still have been facing Sigurd before he dodged, and could compensate with ease.

Edit: Hoplons are also built rounded on a groove that allows some space on the inside, which is why I chose them for a character who wields swords and shields on the same arm.