I know the most common cause of muteness, especially in the old days, was associated deafness. But what reasons can there be for someone to be mute, but not deaf, from birth or very early childhood? It can be something easily correctible now, since this part of the story takes place in the seventeenth century. Ideally it'd be something her children would not necessarily inherit.
I know the main deportations of Hungarian Jews to concentration/death camps occurred in May to June 1944, and from mid-March Hungary was occupied by the German army, both Wehrmacht and SS. I've also found that local gendarmerie were cooperating with the SS in rounding up the Jews.
How plausible would it be for a small patrol scouting mountain villages near the Romanian border to make sure Jews aren't hiding there to consist of several Wehrmacht officers, several Hungarian gendarmes, and one of two SS-men? And if the Wehrmacht officer was sufficiently high up and a veteran of the Eastern front, would he have seniority over the SS-men, or were the two services completely separate?
(And if anyone is curious, they're all getting eaten by vampires. But my vampires are picky and demand to know who they're eating, exactly.)