Would you save Ellie?

[Salnax]

I haven't played The Last of Us, but based on what I know of the scenario, I'd have insisted that the Fireflies waited until she woke up and asked her.

She's supposed to be a fairly intelligent person. From my in-universe knowledge, I might suppose that she guessed that this would be necessary. That could be why she was quiet, especially if she didn't want me to know. Since that could be the case, I would permit her to decide and sacrifice her life if she deemed it worthwhile.