Weldon, a feminist, didn't share social values relevant to Austen's Pride and Prejudice. Thus the values Austen acknowledged, described and ofttimes ironically rebelled against are not Fay Weldon's values. Weldon rebuffs the strident role playing American men and women engaged in when she was young. Yet Austen's ironic rebellion and Weldon's earnest rebuffing don't measure similar attitudes about received social values. Having said this, so it is clear that too close a parallel cannot be drawn between the two women's perspectives, let's look at a couple of examples of how Weldon reshapes the values Austen elucidates in Pride and Prejudice.
Th purpose of Weldon's letters is the initiation of Alice into Literature with a "capital 'L'," into the City of Invention, and into Alice's orientation to the enlightenment manifest in Literature: Weldon asserts, correctly, that Literature enlightens. She fulfills this purpose by escorting Alice on a tour through Jane Austen's life and work.
There is too much concentrated here ... too much of the very essence of civilization, which is, I must tell you, connected to its Literature. It is Literature, with a capital 'L'. (Letters to Alice)
To start, let's define "reshape." To reshape means to form something anew; to form something differently from how it was previously shaped (American Heritage and Collins Dictionaries). This applies to Weldon in that she explains commonplaces of Austen's life and of Pride and Prejudice in new light and by ascribing new motives.
Two of the central values in Pride and Prejudice are marriage and women's economic freedom. These are both best illuminated through Charlotte's remarks and her marriage to Collins. Charlotte makes it clear that her happiest hopes lie in marriage and her economic independence--independence from dependence upon her father and his home--lies in marriage to someone with Collins' present and future prospects: he is intimate with nobility and will be a future property owner.
Then it was the village girl, whose face was her fortune, obliged to marry the rich man from fifty miles away, in order to survive. (Letters to Alice)
Weldon reshapes these values relevant to Jane Austen by speculating that Austen chose not to marry--which Weldon correctly points out equates to choosing not to have children (children were the assumed expectation of marriage)--so that her energies might be poured forth into Literature. This choice in turn reshapes social values by giving a woman worth outside of wifedom and motherhood: Austen has social value by virtue of her imagination; her place in the City of Invention; and her creative story invention. This contrasts with Charlotte who accepts that the surest way to recognized social worth is through marriage.
Weldon reshapes values relevant to women's economic freedom by speculating on Austen's motives relating to her juvenilia. In her youth, she wrote an unfinished novel, as Weldon explains, called Lesley Castle, that she dedicated to her eldest brother Henry. The dedication included a playful ascription authorizing payment of "the sum of one hundred guineas" to Jane, "The Author." Weldon speculates that Austen recognized the monetary value of writing and willfully sought that as her means to economic freedom. This is again in contrast to Charlotte who recognizes her economic freedom (albeit limited economic freedom) is in a marriage to a man with present and future prospects.
There! You see, [Jane Austen is] already conscious that writing is worth money, deserves money, that pleasure for one is work for another, and must be compensated for in financial terms. (Letters to Alice)