Thank you Martha Flatto and others. I have been informed of not one but three unexpected discoveries regarding dates and names in my mother's memoir Franci's War: Prague-Terezin-Auschwitz-Hamburg-Belsen-Prague 1939-1945. The 30,000 members of the FB Group Jewish Genealogy Portal were unbelievably helpful.
They found Coonel Margaret Emmeline Montgomery, the British Red Cross office who beriended her at liberation. She turns up in three other survivor memoirs and was a sister-in-law of Field Marshal Bernard Montgomery.
They found the birth and death dates of her friend Margot Stern Koerbel (1907-1978)
Most movingly they found the records of Gisa Kaufmannova, the little girl my mother adopted in Terezin who was murdered in Auschwitz. Her relatives in Israel were amazed to find out that someone remembered her.
The book will be out in the US in February 2020 and in Czech and Slovak in May 2020.