For the regexp, I think you want to exclude " itself in the string content, except when escaped.  Something like this --- ", followed by either a non " or an escaped character, followed by ":

\"\\([^\"]\\|\\\\\\(.\\|[\n]\\)\\)*\"


But be aware that matching quotations "..." is notorious.  I do exactly that in Info+, but there are a few Info nodes where this highlighting gets thrown off by the occasional lone \" or ?\" in manuals that refer to such programming constructs.

Change face of plain text between double quotation marks in Emacs
I've only seen the movie-version of The Hunger Games, and have yet to read the books. Is it explained where the bodies of the dead Tributes go, if they are removed at all?
