Didn't see anyone comment on it, but the way she draws her gladius is historically correct. Roman legionnaries stood almost shoulder to shoulder, so moving your shield on the side to draw your sword in an arc would expose your chest, so they drew their gladius in that reverse grip, and then flip the wrist. Also, they never swung their gladius. Always stabbed.
Addendum: moving the shield would expose their chest, but also mostly slam it in the next legionnary's face. I forgot to mention that.
Also they used pilum, a throwing spear/javelin which would bend after being lodged in enemy shields. So a throwing spear carried on the shield and fighting spear carried on the side would've been very obnoxious to lug around.
Probably because, if the spear misses the target, you're kinda done, since any opponent getting past the tip has a pretty much guaranteed shot to retaliate.
A Gladius is just more convenient and practical for close quarters. Even if you miss the first strike, you can still pull back and keep trying.
