"I'm p-paralyzed with happiness!"
This line is Daisy's first comment in the novel. Literally, of course, Daisy is declaring to Nick that she is so happy to see him that she cannot rise from the divan. Nick is captivated by her charm.
In Chapter 7, we see Daisy and Jordan on the divan, much as they were in Chapter 1. Here she exclaims,
"We can't move!"
In each case, this literal paralysis suggests a figurative one as well. Despite all that has happened this summer regarding Daisy's reunion with Gatsby, she has not changed much. She is still wondering what to do with her time, what other people plan. At the end of the novel, Daisy remains where she is. She will not leave Tom to run off with Gatsby; she remains safe and secure, and somewhat paralyzed by her great wealth that "imprisons and preserves." She is not paralyzed with happiness, as she claims in the quote; she is paralyzed with wealth. It is Tom's "old money" and its security that prevent her from changing in spite of the fact that her marriage is not a particularly happy or fulfilling one.
The first thing Daisy says in the novel is when she tells Nick on the phone that their move to East Egg was a permanent one.
"This was a permanent move, said Daisy over the telephone, but I didn't believe it--I had no sight into Daisy's heart but I felt that Tom would drift on forever seeking a little wistfully for the dramatic turbulence of some irrecoverable football game."
Nick makes the call not long after his arrival in West Egg. The purpose was to arrange a dinner date with Daisy, his cousin, and Tom, whom he had known in college.
Nick expresses doubt about Daisy's veracity and mentions that he did not know her heart, "I had no sight into Daisy's heart ...". Although Nick focuses on Tom in the rest of the extract, the remark is typical of Daisy. She has the tendency to say things as a matter of convenience and is careless in what she says. There is no real meaning to her words, since she does not feel obligated to attach any real purpose to her remarks. Daisy is spoilt, uncaring and reckless. She is shallow and materialistic.
Daisy wanted immediate resolutions to her problems and so it was when Gatsby, after a month of romance with her, went to war and did not return soon enough for her. Since she wanted resolution, she married Tom, discarding Jay. Although she seemed regretful later, she still went through with the wedding.
After Jay's confrontation with Tom, she acts in a similar fashion when she tells Jay that he "wants too much" and that she loved him too. It is Tom who blurts out that Daisy is lying. Daisy later agrees with Jay that she would be leaving Tom. She does this with "visible effort". However, it soon becomes clear that she has no such intention, since she, after the accident in which Myrtle is killed, seems to plot with Tom.
After Jay's murder, she leaves for some obscure destination with Tom, providing no contact details, typically indicating how little credence even she attaches to what she says.