Yeah, I'd save her.
As for the ongoing discussion regarding Joel and his choice, I'll just give my two cents on the matter: the Fireflies didn't give them a second to even say goodbye to each other. Joel and Ellie went from a very dangerous situation where both almost die to Joel being told "Ellie's gotta die" without any break in between or any sort of acknowledgement between both. I'm not sure what the hurry was (outside the possibility of them being afraid Ellie would refuse, even if chances of this were slim), but it put Joel into a very easy choice to make.
Besides, some people make it seem that by choosing Ellie you instantly doom mankind to extinction. I disagree with this approach, since mankind has pretty much adapted to living with the infected in their day-to-day, as evidenced by the game's prologue (when you walk around with Tess in the city) or when you meet Joel's brother, who is clearly leading a group of people who regain energy power and are going to settle as the good old cities used to, while noting that infected is "the world we live in now". Sure a vaccine would make everyone's life easier, but it's not like there's an immediate need for it by the time TLoU ends.
