How do minor characters like Loretta Bird and Mrs. Peebles help advance the plot and what else do they add to "How I met my Husband"?

Loretta Bird and Mrs. Peebles advance the plot because they are minor, yet, present characters that add insight into the narrator's state of mind.  What I mean by this is that the narrator listens to them when they speak about love, life, etc., (especially Mrs. Peebles) and learns from this.  Loretta is a form of comic relief for me. She's the neighbor that always comes over when she's not invited, etc., because she is bored!  Mrs. Peebles is very important to the plot because she is a great influence on the narrator, in many ways, and is the one who the narrator is working for as a housecleaner, etc.  Near the end of the story, Mrs. Peebles provides some support for the narrator when the "sticky" situation arises between Chris' girlfriend and the narrator.  Mrs. Peebles reprimands the narrator, but keeps her on as her housecleaner.