How is it she never attempted to escape before, or in the instant she found the escalator?
Why did the "Tethered" have to kill everyone? I'm sure she could have saved herself and avoided this mess of a situation...
Also Jordan, I do believe they explained the mimicking. They "tethered" the humans and their counterparts in body, but they couldn't replicate the soul/mind. I assumed the "tether" was a physical bond... I do agree that we could have used more explanation, but I do think they touched upon it rather quickly.