Jordan basically doesn't care about Daisy's past. She is aware of Daisy's affair with Gatsby years ago, since they have been friends since they were teenagers. As the bridesmaid who found Daisy drunk and crying before the rehearsal dinner prior to her wedding to Tom, Jordan knew there was some regret or hesitation on Daisy's part about marrying Tom, but she didn't realize the soggy letter was from Gatsby until
about six weeks ago...when I asked you-do you remember?-if you knew Gatsby in West Egg....she said in the strangest voice that it must be the man she used to know.
Now that Jordan understands the past connection between Gatsby and Daisy, she's willing to help reopen it by asking Nick to host an event at his home with Daisy to which Gatsby could "come over."
Jordan doesn't see any problem in helping Daisy reunite with Gatsby. She knows about Tom's affairs of the past and of his current affair; she doesn't have any proof but wonders if Daisy had any affairs while she and Tom were in Chicago - "Perhaps Daisy never went in for amour at all-and yet there's something in that voice of hers..." Jordan's conclusion about the whole situation: "Daisy ought to have something in her life."