Little was known about the 74-year-old who passed away in an East End care home with no known next of kin.
After the brief service, the sight of Mrs Fishman's lonely grave would not leave the rabbi. He made inquiries within the community, and an anonymous donor volunteered to pay for a headstone. Earlier this summer, Rabbi Mann appealed to JC readers to attend the stone-setting.
Meanwhile, the newspaper tracked down Mrs Fishman's relatives, who travelled from Durham to London for the service last Sunday.
Along with the family were around 35 well-wishers from the Jewish community, including four rabbis.
"Nobody really knew Rita," Rabbi Mann said after the service. "Some people had read about her and just came along. It was mentioned in one or two synagogues on Shabbes, so there were people from those communities who came."
With the help of Fraser and Fraser, a firm of genealogists and international probate researchers, the JC discovered that Mrs Fishman was born Rita Nelson in St Albans in 1938.
Her first marriage was to William Gaunt in Durham in 1958, followed by a second marriage to a Jewish gold merchant, Edward Fishman, in Stepney in 1966, when she converted to Judaism. She had no children.
Mrs Fishman suffered from dementia for several years before she died so little was known about her.
When the JC contacted her sister Mary Lumley, it emerged that the relatives had been estranged for many years.
Mrs Lumley was accompanied at the cemetery by her husband and their three daughters and son-in-law. She said: "It was lovely to see people turn up, even though they didn't know Rita. We were very moved."
Her daughter Ellen Jennings added: "Rabbi Mann was so kind and all the other people who came to the service, too. Hopefully my mam is a bit at ease, knowing Auntie Rita is remembered."
Rabbi Mann said: "Everybody was very friendly to Mrs Fishman's relatives and explained the meaning of the service.
"I apologised to them about not knowing who they were or where they were to get some input from them about the stone."
He added: "Much as I hate the American phrase, I must admit that I felt I brought closure to the matter."
At the graveside, Rabbi Mann talked about the significance of leaving behind an unmarked grave. He said: "It reminded me of so many graves in the forests and fields of eastern Europe where there was also no one left to mourn or put a stone and, in many cases, the names of those people weren't even recorded anywhere.
"I said that it was sad that it could happen now in England and that perhaps we should spend more time looking after the living."
Rabbi Mann said that both he and the family were grateful to the community for its support.
He said: "Those people came along knowing that there was no one to thank them. My faith in the Jewish community and the decency of humanity went up no end."
Rabbi Lea Mühlstein of Northwood and Pinner Liberal Synagogue also attended the stone setting.
She said: "My heart rejoiced. It was heartening to see that although fewer Jews might belong to congregations, when it really matters there are still enough people around who feel an obligation toward every Jew, even if we did not know her."
