Pride and Prejudice (1813) like all of Jane Austen's novels reflects faithfully the socio-economic conditions of what historians term as "Regency England" (1811-20). The family and social structure during this period was patriarchal. The father of a family was also the head of the family. This is most evident from the way the family of the Bennets is structured.
Since women of this period had no right to ownership of property they were financially dependent on their husbands,and hence the urgency and anxiety throughout the novel for the ladies to get married to "young men of large fortune" (ch. 1).
Mr.Bennet's estate is "entailed" to Mr. Collins because Mr.Bennet does not have a son. In 'Regency England' only male heirs could inherit the title and the estate of their fathers. The third paragraph of chapter 50 clearly reveals the 'economic' necessity of having a son and the disappointment at not being able to have one and the consequent predicament which Mr.Bennet faces in not being able to personally meet the financial demands of Wickham:
When first Mr.Bennet had married, economy was held to be perfectly useless; for, of course, they were to have a son. This son was to join in cutting off the entail, as soon as he should be of age, and the widow and younger children would by that means be provided for. Five daughters successively entered the world, but yet the son was to come; and Mrs.Bennet, for many years after Lydia's birth, had been certain that he would. This event had at last been despaired of, but it was then too late to be saving.
In Jane Austen's time women most often (though not always) did not inherit the property of their father. The estate would most often pass on to the eldest son after the father's death. In case there was no son the estate could be 'entailed' to a male relative like Collins in Pride and Prejudice. Although Jane Austen does not explicitly criticize this principle, it is obvious that she disagrees with the convention of entailment, a convention lady de Bourgh did not see need to follow.
A central theme of all her six novels --how much money is necessary for a successful and a happy marriage--is explicitly stated by Elizabeth in Ch.27 of "Pride and Prejudice: "Pray, my dear aunt, what is the difference in matrimonial affairs, between the mercenary and the prudent motive? Where does discretion end and avarice begin?"
In Ch.33 of Pride and Prejudice Col. Fitzwilliam tells Elizabeth "I may suffer from the want of money. Younger sons cannot marry where they like." Clearly hinting at her impoverished status. Col. Fitzwilliam manages to charm Elizabeth within the short period he is acquainted with her. He is obviously a very wealthy man but because he is not the eldest son he will not inherit his father's estate and so he is determined only to marry a very rich woman for the sake of financial security. In fact Elizabeth would have been an ideal match for her, however he clearly hints to her that since she is poor he will not marry her. He is telling lies for he certainly will not "suffer from the want of money;" he just does not want to get married to her because she is poor.
Was Col. Fitzwilliam Darcy "discreet" or "avaricious"?
But most importantly the harsh reality of a bleak future for a dependent unwed old woman is hinted at when Charlotte Lucas' brothers are relieved that Collins is going to marry their sister, for otherwise they would have to look after her in her old age:
the boys were relieved from their apprehension of Charlotte's dying an old maid. [ch.22].