Women are shown to occupy a very shaky position in society compared to men, and, as funny as this novel is, there is no concealing the rather serious presentation of the problems that women face. The only thing that women are able to do in order to move towards some measure of independence is to marry. There is no option of living one's life as a woman outside of that, because unmarried spinsters had to either stay at home and look after their mother (as is the fate of Mary) or depend upon the kindness of family members. This is of course why Charlotte Lucas is so desperate to marry even such a person as Mr. Collins.
However, far more worrying is the way in which any perceived deviance or fault in one woman extends not only to her own character but also the character of those around them. The elopement of Lydia is therefore presented as a very serious threat to all of the Bennet sisters. Note what Mr. Collins writes to them in his "consolation" letter:
They agree with me in apprehending that this false step in one daughter, will be injurious to the fortunes of all the others, for who, as lady Catherine herself condescendingly says, will connect themselves with such a family.
Austen therefore presents her society as being incredibly unforgiving and judgemental towards women. The discrimination of women is therefore shown by the condemnation that Lydia experiences. This is a condemnation that Wickham, even though he is equally, if not more, to blame, does not share. Women are shown to have very few options in this novel, and those few options are further circumscribed by the actions of those around them. One of the reasons Elizabeth is so upset about her sister's elopement is that she recognises that it means she and Jane will be extremely unlikely to ever marry well, showing Lady Catherine's words to be true.