This is an interesting question because Gatsby does not seem to express an opinion about Jordan. In fact, when we see Gatsby and Jordan together for the first time at one of Gatsby's parties, they seem to be mere acquaintances. We learn that Jordan attends Gatsby's parties, but she seems to know no more about him than do the other guests. She tells Nick that Gatsby told her that he went to Oxford, but that she did not believe it. She is quite surprised when Gatsby wants to speak with her privately. We learn later what this conversation is about: he wants Jordan to speak to Nick about setting up a meeting between Gatsby and Daisy.
Jordan does as she is requested. She tells Nick about the summer that Daisy and Gatsby met, and she asks Nick if he will help arrange the meeting. So, in this regard, Jay Gatsby is right about Jordan. She will carry through with his request, and so will Nick. But this is the extent to which Jordan has meaning to Gatsby. Jordan is only a means to an end. He values the fact that Jordan knows Nick and Daisy, but he seems to have no opinion of her character.