That fourth--and most important--difference is clearly stated in the remarkable opening sentence of the novel: Nina Balatka was a maiden of Prague, born of Christian parents, and herself a Christian--but she loved a Jew; and this is her story.
Marriage--even worse, love--between a Christian and a Jew would have been unacceptable to Victorian British readers.

Blatant anti-semitism was prevalent--perhaps ubiquitous--among the upper classes.
Let us consider the origins of this anti-semitism.

Jews were first allowed into England by William the Conqueror.

For a while they prospered, largely through money-lending, an occupation to which they were restricted.

In the 13th century a series of increasingly oppressive laws and taxes reduced the Jewish community to poverty, and the Jews were expelled from England in 1290.