Compare Ophelia in Act 1 and Act 2 in Hamlet

In Act I, everyone warns Ophelia to stay away from Hamlet. Her brother tells her Hamlet is out of her league.... that he will never marry her, thus, she must guard her virginity and good name. When she speaks with her father, he says the same.

In Act II, Ophelia puts herself in a situation where she is alone with Hamlet. She is frightened by Hamlet's words and behavior, and then goes onto tell her father that she has cut off all conact with him. Polonius, however, comes to the conclusion that Ophelia is responsible for Hamlet's strange behavior and runs to report to the king.