"Drummer" was once a well-known term for traveling salesman. This unnamed drummer is imagined by Jefferson observers to have oversold some commodity to Wallstreet Panic Snopes, thus making it necessary for him to borrow money.
Miss Wyott is a teacher in Jefferson, but the narrative notes that her "own people" - that is, her ancestors - "had come from the country (her own branch of it remained there where they had owned the nearest ford, crossing, ferry before Jefferson even became Jefferson)" (154). (In The Reivers Faulkner re-names the family that owns this spot Wylie.)
Although she is never named, Mrs. Wallstreet Panic is memorably characterized. When she first appears at school in Jefferson, the teacher, Miss Vaiden Wyott, instructs Wall that "this is she. Marry her." He does. His wife is described as a "tense fierce not quite plain-faced girl . . . and a will if anything even more furious" than Gavin's in opposing the rest of the Snopeses (154).