Update on my own research...I was incorrect about the name of my great grandfather's brother's wife; Rose was his second wife!

Just recently, I learned that my great grandfather had a sister named Rose (who married a man with the last name of Karp), a half sister named Fannie Alpert (Alpert being her married name) and a sister who did not come to the US; she perished in the Holocaust.

It is now my mission to try to find information on the sister who perished, as well as more on Fannie.

Have found more about Fannie's family but am still trying to find out more about the mystery sister who perished in the Holocaust!