Who is Martha and why does she visit the Wiesel family in the ghetto?

At the beginning of Night, Elie Wiesel's memoir of his experiences in Nazi concentration camps during World War II, the Jews of Sighet, Wiesel's hometown, are in denial about the threat which the Nazis pose to their way of life. As late as the spring of 1944 they did not believe the threat was real. They ignored the warnings of Moshe the Beadle who had miraculously escaped death in the forests of Galicia and felt it his duty to report the atrocities he had seen. He is greeted with derision as the people look on him as simply crazy. When the ghetto is established, the Jews still cling to the idea that all will be well. Even Elie's father seems to ignore the signs and, when the family's servant Martha pleads with him to bring his family to her village for protection, he refuses. He does, however, tell Elie and his older daughters that they may go with Martha if they wish. They refuse and the family is ultimately deported to Auschwitz.