Answer:
Sherry does not know that her friends are about to see her in a messy state.
Explanation:
Dramatic irony is used to show that the audience knows more than the character on stage. A character does or says something of greater importance than he or she knows. The audience, however, understands the meaning and importance of the act or speech. When she says that she has not done a thing for her birthday, she does not know that she is about to celebrate with her friends. Sherry's situation creates humor in this passage.
