Elizabeth, immediately recognising the livery, guessed what it meant, and imparted no small degree of surprise to her relations by acquainting them with the honour which she expected. Her uncle and aunt were all amazement; and the embarrassment of her manner as she spoke, joined to the circumstance itself, and many of the circumstances of the preceding day, opened to them a new idea on the business. Nothing had ever suggested it before, but they now felt that there was no other way of accounting for such attentions from such a quarter than by supposing a partiality for their niece

Mr. and Mrs. G have an "Eureka" moment with the realization that is smitten with their niece. They use the visit to ascertain the feelings of Darcy and Elizabeth. Darcy seems fairly easy to read for the Gardiners, but with Elizabeth they cannot fully gage her feelings.

To Mr. and Mrs. Gardiner [Bingley] was scarcely a less interesting personage than to herself. They had long wished to see him. The whole party before them, indeed, excited a lively attention. The suspicions which had just arisen of Mr. Darcy and their niece directed their observation towards each with an earnest though guarded inquiry; and they soon drew from those inquiries the full conviction that one of them at least knew what it was to love. Of the lady's sensations they remained a little in doubt; but that the gentleman was overflowing with admiration was evident enough.

Mrs. Gardiner looked at her niece, desirous of knowing how she, whom the invitation most concerned, felt disposed as to its acceptance, but Elizabeth had turned away her head. Presuming, however, that this studied avoidance spoke rather a momentary embarrassment than any dislike of the proposal, and seeing in her husband, who was fond of society, a perfect willingness to accept it, she ventured to engage for her attendance, and the day after the next was fixed on.

I have to admire the Gardiner's restraint from questioning Elizabeth