What are the personal pronoun and the possessive pronoun in Ms. Kowalski signed her autograph on this theater program?

There is no personal pronoun in the example sentence.

There is no possessive pronoun in the example sentence.

The pronoun in the sentence is her, a possessive adjective.

The difference between a possessive pronoun and a possessive adjective is:

• a possessive pronoun takes the place of a noun for something that belongs to someone or something;
• a possessive adjective takes the place of a noun and comes just before a noun to describe that noun.

Examples:

Ms. Kowalski signed her autograph on this theater program.

The autograph on this program is hers. (possessive pronoun)