I have looked through the Briston parish registers, and couldn’t see any children baptised there with the surname Gant, or any variation, during the time frame we are looking at.
The couple mentioned as Susan/Charlotte’s parents (William Gant and SarahWells) married in Fakenham on the 27 November 1804, had several children baptised there, including a Susan (no mention of the name Charlotte) on 18 April 1816
http://www.rootschat.com/links/01ehk/This Susan Gant went on to marry a Henry Bugdell in 1834 at Fakenham.
They had children in Norfolk, then went on to live in Essex.
Also noticed that in later censuses, right up to 1891, Charlotte Cohen names her place of birth as Wood Norton, but as Chris says in earlier posts, there are no baptisms for Gants in either of those parishes.
I wondered whether the couple married after the children had been born, prompting the "mass" baptism that Trish found ..... but still haven't found a marriage.
There is a very interesting newspaper entry from the Norfolk Chronicle, June 1859, which mentions that Joseph Cohen requested his wife to see that he was buried as a Jew. It's a rather sad piece, inferring that Joseph "having married a Christian woman" was then an outcast, but it appears he did get his wish and was buried in the Jewish cemetery (though the rabbi refused to perform the ceremony). How sad.
Yorkslass