It is not needed because the questions could be more concisely put as where is she/he?. She 's she's she has so my question is should she has be contracted as she 's in the above example like in the. In your example, she is being emphasised.
She was in the movie cat on a hot tin. She was in on the drama when the conman showed up at the stage door. If joan is the person who answered the phone, should she say this is her or this is she?
Upon answering the telephone, the person calling asks if joan is available. When referring to google ngram, i get 3 possible combinations of she's: This redundancy, and the efforts of seventeenth and eighteenth century. Taken from the free online dictionary:
What is the correct (grammatical) simple past and past participle form of the verb quit? She had been working for the previous five years with an advertising company means that she had worked there for 5 years and was still continuing to work there. (she has quitted her job.) she quit her job. Is it quit or quitted?
The difference is that she's and similar shortened forms are used in colloquial speech, but not in certain cases.