Daisy was not completely prepared to marry Tom, according to Jordan. When the wedding was about to take place, Daisy receives a letter from Gatsby that sends her into a tearful, sobbing swoon.
Daisy refuses to let go of the letter even as she takes a bath before getting dressed for the wedding. The letter gets soaked, by tears and bath water, and falls to pieces.
Although Daisy does not drink, the night she receives the note from Gatsby she drinks herself into a stupor; and after sobering up in a tub and succumbing to the influence of her mother, she decides to abandon Gatsby and marry Tom. Crucial to understanding the importance of this scene is the conventional resolution of the conflict between love and money. (eNotes)
The story Jordan tells shows that Daisy has essentially given up on love. Later, with Gatsby again, she hopes to regain this first "love" but only because Gatsby has managed to become wealthy.
We see this dynamic again when Daisy weeps over Gatsby's "beautiful shirts". In that scene, Daisy weeps for reasons that remain obscure, but we might guess that she regrets the compromise she once made in choosing money over love. Had she chosen Gatsby back then, she could have had both love and money. Instead, she chose Tom/money, and finds herself living a life of the repetitive drama becoming the cheated wife of a philandering man.
Jordan's story suggests, however, that Daisy was truly drawn to the idea of running away with Gatsby before he had money. She almost chose love instead of money.