ive seen a couple of these takes, and it amazes me that people would think, a bounty hunter, hunting mutants, and bio-freaks, cyborgs and the like, would go into battle without armor. Let alone in some dystopian future.

In their defense and just like bikini armor, no one would expect a person alone would hunt packs of creatures stronger than them without a strong plot armor.

In the movie, she lost her armor in an explosion. That's also why her pants are ripped up.