Ethnic Germans have formed a minority in Romania for centuries. In 1930, when Hanna would have been there, the German population was estimated at 760,000. They were collectively represented by the German People’s Party from 1935-1938, but this was dissolved under orders from Berlin.
At the end of WW2, tens of thousands of ethnic Germans were required to leave Romania on Soviet orders, to provide forced labour as war reparations; several thousand people died. Today, ethnic Germans in Romania are represented by the respected Democratic Forum of Germans in Romania.
Here is some more information about Germany's present day relations with Romania.
This documentary explores some of the issues facing older ethnic Germans in Romania today.