Wohlgemuth-Katz family names and towns

Here's a summary of the new Wohlgemuth-Katz information. 

Elly Ringel's father was Isaak Wohlgemuth, born 1865 in Stargard near Danzig. His parents were Leopold Wohlgemuth (dates unknown) and Friederike Paechter (1938-1910, died in Danzig). Isaak had a sister Rosa (or Roza). 

Elly's mother was Betty Katz, born 1875 in Kolberg, West Prussia, about 150 miles west of Danzig on the Baltic coast. Betty's parents were Kolberg merchant Louis Levin Katz (b. 1839) and Henriette Müllerheim (b. 1849). Betty had a sister Klara born a year later and then Henriette died the year after that at age 28. Louis remarried and the children were raised by the second wife Paula Perl Lewy. Paula also died when Betty was 18 and Louis took a third wife, Bertha. 

Betty and Isaak were married in Kolberg in April 1898. By now, he was living in Elbing near to Danzig, and that is where they began married life together. Their first child was Elly Wohlgemuth, born July 3, 1901 in Elbing. A second daughter Hilda Wohlgemuth was born Jan. 20, 1906 in Danzig. 

Betty's sister Klara married Siegfried Jacobson in 1904, but there is no record of children. 

We had heard information that Isaak was in business in Königsberg, 100 miles to the east, and that the family lived there. That is possible, but pending some evidence about Königsberg I'm inclined to believe the family stayed in either Elbing or Danzig until they later moved to Berlin when Elly was of marriageable age. 

Isaak died in 1929 and is buried at Wiessensee. I am pretty sure his sister Rosa is buried near to him. 

Yad Vashem has a centralized database of Shoah victims that includes all or most of those deported on more than 60 transports from Berlin to the east between October 1941 and early 1945. I can't find our Betty Katz Wohlgemuth in the database.