how did there marriage change the lives of 3 sisters?

Scholars suggest that social mobility is the primary theme in all of Austen's novels; this idea seems especially apparent in Mansfield Park. The opening chapter, in which the three Ward sisters marry men of very different social categories (high, middle and low), fixes this construct as the novel's primary theme. Maria Ward moves above her designated social station by marrying the baronet, Sir Thomas Bertram of Mansfield Park; the middle sister, Mrs. Norris, marries at a more socially appropriate (middle) station; the youngest sister marries a common sailor, Mr. Price, who will in time become an unemployed drunkard. Austen utilizes this triad to illustrate that high morals do not necessarily come with high social standing, and that people born into lower social ranks should be given the opportunity to move up through their moral behavior.

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