Hi cousin Jon, thank you for the update.
I added her photo, which was in her passport application. Do you know if she ever married (it appears not) and which year and where she died? Do you know her original Hebrew/Yiddish name?
Also, interesting fact. In her passport application it appears as if she was born in Moscow, Russia in 1891. This is an interesting lead because very few Jews were allowed to settle in Moscow at the time, which was beyond Pale of Settlement. Even to stay in Moscow, Jews had to have good documented reason (being a student, merchant or former soldier). Her parents were of course from the shtetl of Gorki, as were our Dobrer ancestors. The metric book for the Rabbinate of Moscow dated 1891 is posted online, I went through it and couldn't find a record of Rose's birth. I did however find records for other Zeitlin individuals from Gorki, who were likely to have been the same family.
I knew her well. She visited from NYC every year and cane for her book tour. She also always visited my great aunt Ida Zeitlin Nadejen. She never married. She spent her career as a teacher in New York. Her passion was Palestine and she went frequently both alone and with Szold. I have no clue about Moscow birth.
Her brother, Jacob was most famous writer, scholar in family. Prof at University of Illinois at Champaign Urbana.
Their sister, my grandmother Lottie, lived with us till her death.