I mentioned in my post about Frederick Weiss' journey to England from India that he stayed at 73 Upper Norton Street when he arrived in London. I worked out last night that this was the home of some relatives. Gustavus Von Holst (uncle on Fred's mother's side and grandfather of the composer Gustav Holst) was a professor of music, and this is where he lived (and probably worked) with his wife Honoria.
And I found another piece of circumstantial evidence that Caroline J Hughes is the Caroline Weiss from my family. Caroline was the third child in the Weiss family, the eldest being Adelaide. Adelaide married James Sheldon and they had at least five children, one of whom, Adelaide M Sheldon, was born in Blackheath, Kent, England (now a part of London near Greenwich). James was a missionary with the Church Missionary Society (CMS) in India and they lived there between 1855 and 1883. During this time their daughter Adelaide was born (in about 1869), presumably when they were back in England for a visit. In about 1868 Caroline and Henry Hughes had a daughter Elizabeth, also born in Blackheath, Kent, England. The Hughes had not long been in England, and appear to have not yet settled in Bath. It is not unlikely that the two families might have spent time together (or even stayed together) during this period when both sisters were pregnant with their daughters. As I said, it's circumstantial, but another little piece of possible evidence nonetheless.