Thanks to the #TolkienAncestry studies we can find so many interesting stories...
I have probably found Mrs. E. R. Ehrhardt from J.R.R. Tolkien's letter #349 (from 1973; in the Letters her surname is mistyped as Ehrardt). She was Rev. Arnold Ehrhardt's wife. Her full name was Edit R. Ehrhardt, née Hahn (1905-1997). Rev. Arnold Ehrhardt (1903-1965) was an anti-Nazi pastor of half-Jewish ancestry. The Ehrhardts emmigrated to England in 1939 because of the Nazi terror. Mrs E. R. Ehrhardt was an editor and author in England. Arnold Ehrhardt was born in Konigsberg, East Prussia.
»I do not understand why you should wish to associate my name with TOLK, an interpreter or spokesman. This is a word of Slavonic origin that became adopted in Lithuanian (TULKAS), Finnish (TULKKI) and in the Scand. langs., and eventually right across N. Germany (linguistically Low German) and finally into Dutch. It was never adopted into English.«
(J.R.R. Tolkien, letter #349 to Mrs. E. R. Ehrhardt
Saying the truth I understand why Mrs. Ehrhardt associated the Tolkien family name with the element TOLK, 'an interpreter, spokesman'. More about Rev. Arnold Ehrhardt can be found on Wikipedia (here).