The main thematic conflict of the novel, the struggle between social convention and independence in the life of Isabel Archer, comes to a miniature climax in Chapter 7, when Isabel and Mrs. Touchett argue about whether Isabel should stay up talking to Ralph and Warburton without a chaperone. Isabel rebelliously wants to disregard custom and stay downstairs, but to Ralph's surprise, she docilely obeys Mrs. Touchett.
The implication is that for all that Isabel considers herself independent and seems independent to those around her, she also has a desire to fit in and will not routinely thwart social convention even when it grates her. In fact, Mrs. Touchett, who enforces social convention in this scene, is in many ways far more independent and rebellious than Isabel—after all, she is separated from her husband and lives alone in Florence, making her own decisions and forming her own opinions. Isabel is a charismatic and individualistic character, but she will never really achieve this level of autonomy.