I voted for Mrs. Garrett, who wasn't really a maid or a housekeeper but more of a den mother. A sometimes strict, but always caring, authority figure to a bunch of mischievous, but oddly lovable young girls.
Needless to say, I also picked it because I've been calling Sara of Roommates, Mrs. Garrett for years now. She hated it at first, but seems to have come around to it. I try to call her Alice or Hazel too, sometimes, but those haven't stuck.