okay okay okay okay. let’s talk about being a “beautiful little fool.” Here’s what Daisy is talking about.
So she has spent her entire life in the lap of luxury. It is IMPOSSIBLE for her to be happy without money, to the point where the man who has spent the last five years pining for her has to bootleg his way to the top in order to even DREAM of having a chance with her (but more on that later). Daisy Buchanan is shallow and narcissistic, and won’t get a divorce from the man she hates because she’s afraid of what the other high-societies will think of her. When she does go to Gatsby’s party, she’s uncomfortable because even though it is lavish and Gatsby is OBVIOUSLY throwing around his wealth, the people at the party aren’t a part of the society of wealth she comes from. When she says she wishes her daughter will be a fool, she’s saying she doesn’t want her daughter to be smart enough to realize her troubles, like Daisy thinks she herself has.
In reality, though, Daisy IS a fool. She’s shallow and fickle and STUPID. Being a “beautiful little fool” is NOT a good thing. It is a very, very bad thing, and the point of that line is for the reader to realize the IRONY in Daisy’s statement, and at the same time pity her and hate her for being such a fool herself.