D'arcy Wenn and D'socra Wenn see Hannah more of as a member of the family than as hired help, as they have a very close and loving mother/daughter type of relationship—especially considering D'arcy never really knew her actual mom and Hannah never had children of her own. D'socra relies on Hannah to run his household in his frequent absences.
Hannah is traditional and is very protective of D'arcy, as she often worries about her safety, even though she knows that D'arcy can take care of herself (mostly). And D'arcy, ever appreciative of Hannah's concern for her, takes Hannah's opinions into consideration, (usually) following her housekeeper's wise advice. Hannah's a very clever and brave woman in her own right, though---she's made homemade burglar alarms, and courageously stands up to intruders and other miscreants when Mr. Wenn isn't present.