Who is The Reverend Foster Olive, Lizzy Olive from The Persian Pickle Club and what is their importance?

The town minister and his sister play relatively minor roles in the narrative, but their upright and rigid judgmental morality is an effective and telling contrast to the thematically central, more ambiguous morality practiced by the members of the Persian Pickle Club (see "Themes"). It's interesting to note, in this context, how frequently the Club dodges involvement with the Reverent and his sister, and how they refuse Lizzy membership. The question, of course, is whether this makes the Club on some level as judgmental as the people they claim are TOO judgmental.