I suppose the Marx brothers & Al Jolson were Holocaust survivors too. They were alive, in the US, when Hitler was alive and the Holocaust was ongoing, by whatever definition you want.
So you discount the experience of a German Jew, born in 1924 and living as a child user Nazi rule from 1933 until she was rescued from Germany in 1939? How are the Marx brothers (all of whom were born in the US, and did not spend a moment living under Nazi rule) at all relevant?
I think Epstein’s Jew-hating activism is repugnant. But I think it is dangerous to go around diminishing her experience under the Nazis. If anything, her experience as a survivor makes her subsequent work all that much MORE repugnant.