How does Mrs. Gardiner give advice in such a way that it is not resented? How is Mrs. Gardiner’s approach different from Mrs. Bennet’s?

Mrs. Gardiner gives advice in a kindly fashion, and she does it in private. She hinted rather than demanded, and she pointed out the duty of respect rather than the duty of following orders. At the end of their conversation;

"Her aunt assured her that she was; and Elizabeth having thanked her for the kindness of her hints, they parted; a wonderful instance of advice being given on such a point without being resented."