In The Great Gatsby, one example of Daisy's cynicism is evident when she tells Nick the narrator about the birth of her daughter.
She explains how dissappointed she was when the baby turned out to be a girl instead of a boy. She tells Nick that she mentally gave in to her daughter's fate. Very well, then, she says, her daughter must grow up to be a beautiful little fool. That's the only hope for a female.
The idea is that Daisy, and her daughter, are women in a man's world. Women had only recently even received the right to vote. Divorce laws were heavily weighted in favor of males. Education was rare for females. Daisy suggests that the only way for a female to get ahead in American life at the time is to marry wealthy, to be a beautiful little fool, look pretty, do what a man tells her, and marry wealthy. The American Dream is limited only to men. The only way women can take part, according to Daisy, is to marry a wealthy man.
That's what Daisy had to do, of course, and she regrets that her daughter will have to do the same.
Of course, only some wouldcall this cynicism. Others would say it's realism.
Cynicism is defined by the Merriam Webster dictionary as "beliefs that people are generally selfish and dishonest."
Daisy, for good reason, believes her husband Tom to be dishonest. She is aware that he is unfaithful and a liar. In chapter six, when Daisy and Tom attend Gatsby's party, Tom tells Daisy he's going off to eat with another group of people because a man with them is telling funny stories. Daisy responds, "Go ahead, and if you want to take down any addresses, here's my little gold pencil." Moments later, she tells Nick "the girl was 'common but pretty,'" indicating that she believes Tom went off with another woman at the party.
In chapter seven, Tom takes a phone call in another room, raising his voice and scolding someone (presumably George Wilson) for bothering him at lunchtime about the sale of his car. In the next room, Daisy says "Holding down the receiver," "cynically" to Nick and the others. She believes Tom is on the phone with his mistress.
Later in chapter seven, Daisy calls Tom out for his selfishness and deception, telling him "You're revolting," and implying that they'd left Chicago because of a scandal he'd been involved in, as a reply to his insistence that he "love[s] her all the time."