Dear Barbara,
I'm doing research on Rosey Pool, who was in the resistance group Van Dien, together with Uschi Rubinstein Littmann. I'm not sure if she's still alive.
Uschi Rubinstein-Littmann has been interviewed by Ben Braber for his new book. See link on Google Books:
https://books.google.nl/books?id=-Ha5BwAAQBAJ&pg=PA143&dq=Uschi+Rubinstein-Littmann&hl=nl&sa=X&ved=0CDIQ6AEwAGoVChMI1JrZ87CZyAIVwlwaCh05rgjW#v=onepage&q=Uschi%20Rubinstein-Littmann&f=false
Perhaps you can contact him via his website: http://benbraber.com/
Good luck with your research, Lonneke