The text of the novel establishes that Daisy Buchanan is a member of the upper class in American society. She grew up in her father's fine house, married an enormously wealthy man, and pursued a privileged lifestyle among other members of her upper class. On two particular occasions, Daisy's own words and actions clearly reflect her social position. In Chapter I, when Nick comes to dinner, she expresses at one point the idle boredom of the rich. When Jordan Baker suggests that some social activity should be planned, Daisy responds, "What do people plan?" She asks this in a helpless voice. Daisy has no work to do and no interests to pursue; her only role in life is to be rich.
Later in the novel, Daisy attends one of Gatsby's wild parties attended by the kind of people with whom she has no social contact, particularly "show business" people. She finds their uninhibited behavior quite bizarre; she is "offended" by them. She observes without participating, much as one might observe a foreign species. Commenting upon Gatsby's guests, Daisy makes this assessment:
Lots of people come who haven't been invited . . . They simply force their way in and he's too polite to object.
Daisy feels contempt for these people, indicating the superior attitude of her social class. Nick says this about Daisy's upper-class sensibilities:
She was appalled by West Egg, this unprecedented "place" that Broadway had begotten upon a Long Island fishing village--appalled by its raw vigor that chafed under the old euphemisms . . . .
Daisy is quite uncomfortable outside her own privileged world and contemptuous of those "beneath" her social position.