Was Rachel S Stein in the movie Black Book a living person?

In my research I was unable to find any reference to a real person like the one in "Black Book" named "Rachel Stein". Considering she would be over 80 years old now (if real and still alive), and I wouldn't be surprised if she didn't want her real name used. The name "Rachel Stein" is very common, so the question comes up "What was her real name?"