What type of noun is her?

The Word 'hers' is not a noun.

The Word 'hers' is a pronoun, a possessive pronoun.

A pronoun is a Word that takes the place of a noun in a sentence.

A possessive pronoun is a Word that takes the place of a noun that belongs to someone or something.

The possessive pronouns are: mine, yours, his, hers, its, ours, theirs.

Example: Mona lives on this street. The house on the corner is hers.

A possessive pronoun should not be confused with a possessive adjective. A possessive adjective is a Word that takes the place of a possessive noun to describe a noun as belonging to someone or something.

The possessive adjectives are: my, your, his, her, its, our, their.

Example: Mona lives on this street. Her house is on the corner.