Is it she?
how about"est-ce elle?"
I think it would have to to be est-ce que c'est elle. you just put est-ce que in front of the original question.
why not C'est sa?
is it her portfolio, is it her car? is it her jacket? is it her responsability?.. this sentence needs one more word
Is it she? and the casual form "Is it her?" translate to the same French question. Some English phrases don't distinctly translate. For example, "You eat", "You are eating" both translate to "Tu manges".