Fascinating as it may sound, this is certainly not news. One interesting account of Dickens' correspondence with the woman, Eliza Davis -- whose husband bought Dickens' house -- is to be found here.
Interestingly, the author explains what Dickens meant when he told Davis, "See what I make of this in my next novel" (a remark which is left rather cryptic in the Post):
In Our Mutual Friend, his last complete novel, whose serial publication appeared in 1864, a year after his exchange with Eliza Davis, Dickens introduced Riah, a good Jew. This was almost certainly done in atonement for her accusations....This is only a very partial exoneration; Riah,who is also a money lender, is criticised for being 'stilted,' 'unreal,' too feminized and too much of an outsider, and the changes to Fagin were really only cosmetic. But isn't this already more than you can expect?
Riah seems to have been modeled on a good Jew plucked from an eighteenth-century play that he had read a number of times as a boy and that he had once considered producing...
Dickens harps on the goodness of this Jewish money-lender, who is mistakenly perceived to be evil because of the manipulation by a shadowy Christian vulture.
Riah's second role in the story is to serve as a kindly "fairy godmother" to a pair of poor, forlorn and downtrodden young women, finding a job for one of them in a Jewish-owned factory. Riah just oozes goodness."