When Elyot implores Sibyl that they must leave the hotel, Sibyl is uncharacteristically firm and stubborn about staying. What happened throughout the act that may have given her more of a backbone?

Earlier in Act I, Elyot makes a dig at Sibyl about her femininity and how she seems to want a man and woman to fit into a certain "type" (for example, the man must be very masculine, while the woman must be very modesty feminine). It can be read that, because of Elyot's remarks, Sibyl decides that she should be able to stand her ground and show Elyot that she is more than a kitten, as he called her earlier. Had Elyot not made a big deal about Sibyl's tendencies, there is a good chance she would have simply gone along with Elyot's desire to leave.