Even in season 1 she could have easily been cut and it wouldnt have changed the story at all. The episode where she is introduced is just a filler episode that exists solely to introduce her character, and when she is brought back at the end she contributes nothing that couldnt have easily been done by any other character. I pretty sure her greatest contribution after being brought back at the end of the season was to shoot a wall that allowed the good guys to try to escape after they were pinned down in a building. This was after the antagonist inexplicably gave them the old "you have til nightfall to surrender", despite having a vastly superior force that could have overrun them in minutes.