In The Great Gatsby, Daisy is presented as being willful but uncertain and hollow. She often tries words and mannerisms on. For example, when, in Chapter 1, Jordan says: “Let’s plan something.” Instead of coming up with her own idea she asks: “What do people plan?”
In that sense, we can say that she’s acting. Because she’s protected by money, none of the choices she makes are very risky, or matter too much one way or the other. Is that natural? It’s presented as being inherent to her social class.