Is This is a possessive adjective?

The form 'hers' is a possessive pronoun, a Word that takes the place of a noun that belongs to someone or something.

In the sentence, "Is this drawing hers?", it is easier to see when it is in the form of an answer, "This drawingis hers." The pronoun hers is taking the place of the noun drawing as a predicate nominative (a noun or a pronoun following a linking verb that restates or stands for the subject, drawing = hers). The parts of speech are the same in the form of the question or the form of the answer.

A possessive adjective is placed before a noun to describe the noun as belonging to someone or something. The corresponding possessive adjective is 'her'. Example: "This is her drawing." Here the predicate noun is drawing (this = drawing).