In answering this question, I'd like to focus on the consequences (or lack thereof) Daisy faces as a result of her recklessness. In doing so, I'm not saying that Tom or Gatsby's guests aren't reckless or don't face consequences. Rather, I merely find Daisy's experience to be the most interesting and important to the overall plot of the book (but that opinion is affected by my own personal context, and other readers might find other details of the story to be more important). Overall, Daisy's recklessness leads to Gatsby's death, so her story is particularly remarkable.
After a distressing confrontation with Tom (at which point Daisy is basically bullied into staying with her overbearing husband), Daisy drives home with Gatsby and, because she's driving recklessly, she hits and kills Myrtle Wilson. This action leads George Wilson, Myrtle's husband, to shoot and kill Gatsby at the end of the novel. As a result, Daisy's recklessness leads indirectly to Gatsby's death.
There are two ways to interpret the consequences for this action; on one hand, it's possible to argue Daisy faces no negative consequences. Gatsby takes responsibility for hitting Myrtle, and he is the one subsequently murdered. We can guess Daisy experiences a certain level of guilt and emotional distress on hearing of Gatsby's death, but we're never directly told exactly how guilty she feels. Instead, we witness Gatsby paying the ultimate price because he took the blame for Daisy's recklessness, which makes his death even more tragic. On the other hand, it's also possible to argue the consequence Daisy faces is that she is locked into a presumably unhappy marriage with Tom. Whether that consequence is more negative than Gatsby' death is up for debate.
F. Scott Fitzgerald's The Great Gatsby is filled with reckless actions performed by careless people. Gatsby, Tom, Daisy, and even Nick are all reckless in some way during the course of the narrative. As such, searching the book for examples of this recklessness is of vital importance, and identifying who pays the price for this recklessness is even more important.