How is Elizabeth ambivalent about Mr. Darcy returning with Mr. Bingley?

Elizabeth, after having seen him while on vacation with the Gardiners, is sure that Bingley is still partial to Jane, and thinks that perhaps Mr. Darcy may have told Bingley that he now approves of the match. At the same time Elizabeth begins to hope that Darcy's affections for her are not shaken. When they come in, Elizabeth is pained by Mrs. Bennet's cold reception of Darcy in comparison with Mr. Bingley, considering how much she owes to Darcy.