What a triumph for him, as she often thought, could he know that the proposals which she had proudly spurned only four months ago, would now have been gladly and gratefully received! He was as generous, she doubted not, as the most generous of his sex; but while he was mortal, there must be a triumph.

Elizabeth admits that her feelings for Darcy have changed to the extent that she would now accept his proposal. This realization comes in the midst of the whole Lydia scandal, before she knows of his involvement in Lydia's elopement. Therefore, Elizabeth believes her change of heart will come to nothing.