I read in a family letter from Jozef Sanetra (dated 1961), that Alfreda Mazurkiewicz was from Kolbuszowa, Poland. From what little I have seen about Kolbuszowa, it was a Jewish settlement, and heavily destroyed during Nazi occupation. After the war, in abt 1956 (as a widow), Alfreda left Zywiec, and moved back to Kolbuszowa, then later to northern Poland. I do not know if Alfreda was Catholic or Jewish. I only know that the Sanetra's were Catholic.
I have struggled to find anything on Alfreda's family. Her marriage certificate to Adam is the only proof I have that she was in the United States. (Have since found her immigration into and out of the country) And then in 1922, Alfreda and Adam went back to Poland, and bought a house in Zywiec. Adam opened a joinery shop and was a finish carpenter. But they lost all they had when there was a money change about 1924-1925.
On the Ellis Island manifest, in 1923, Adam states he is going to live with his Brother-in-law Karol Janik 1058N. Marshfield Ave, Chicago, IL. None of Adam's sisters married a Janik, so I figured Julia is probably the sister of Alfreda.