After what
Phineas Gage survived, namely a giant railroad spike penetrating his skull, it's certainly not impossible that Carley would live. Implausible, but not impossible.
However, I doubt she or Doug are coming back for practical and thematic reasons. Lee is gone now, so any interactions with a new protagonist would have little meaning, and without medical help such as Gage received I can't imagine her surviving. And anyway, an injury like that can damage your personality severely depending on what part of the brain it hits. She would likely behave erratically, at least for a number of years, at best.
I would love to have her, Ben, and Kenny back, besides Omid and Christa (whom I never doubted would survive from the moment I saw them), but it's just not happening. It's just too implausible.