In the story "A Rose for Emily", by William Faulkner, what is the significance of the mention of Old Lady Wyatt and Miss Emily's cousins?

Old lady Wyatt is mentioned but never actually appears in
William Faulkner's short story, "A Rose for Emily." Wyatt is Emily's kin from Alabama,
and she has apparently suffered from mental instability since she is referred to as "the
crazy woman." It is significant since it can be inferred that mental disease runs in the
family, and that Miss Emily may also have inherited it and may be suffering from it. The
cousins, relatives of old lady Wyatt, appear in the story when they visit Miss Emily
during her affair with Homer Barron, hoping to convince her to end the relationship.
They had had "a falling out" with Emily's father over the family estate in Alabama, but
Emily's condition was deemed important enough for the cousins to be summoned (by the
preacher's wife, who had contacted them). The cousins remained in Jefferson for a week,
but after they left, Homer immediately returned.