The novel closes with a reminder that the most important attachment in the novel is not that between any man and woman, but between the two sisters. The sisters decide to live side-by-side together with their husbands at Delaford, thereby affirming the mutual respect and affection, which has kept them close throughout the entire novel.
Ultimately, both sisters end up married to the novel's only second sons. Edward Ferrars, although strictly speaking the firstborn, is disinherited by his mother; as John Dashwood remarks, "Robert will now to all intents and purposes be considered as the eldest son." We know that Colonel Brandon is a second son because he has an older brother who married his old sweetheart, Eliza, many years before the novel's plot begins. Whereas these characters are the heroes of the novel, all the eldest sons, including John Dashwood, Robert Ferrars, and Colonel Brandon's older brother, are cast in a negative light. In Austen's day, the eldest sons were the ones who inherited all the family property according to the laws of male primogeniture. However, in spite of these inheritance laws, it is the second sons who ultimately find contentment in the novel; thus, they make happy lives for themselves despite societal and financial constraints.