Minnie is Mr. Omer's daughter. We first meet her when David is traveling home to his mother's funeral and he meets the Omers, who are preparing Mrs. Copperfield's body for burial. As the Omers travel with David in their cart to Blunderstone, David is amazed that they can carry on a normal conversation with one another while he is feeling so sad. It is the first time that David realizes that the world does not turn on David alone, and that other people have joys and sorrows of which he has no part.
In addition to being a nice lady whom David sees from time to time when he goes back to Blunderstone, Minnie has one other major function. Her father, Mr. Omer, is the one who takes Emily on as an apprentice. And Minnie becomes the Area Woman who voices the community's collective opinion of Emily: before Emily runs away, she disapproves of Emily's flashy, high-and-mighty ways. And after Emily runs away, she calls Emily a bad girl but then cries with worry over her fate.
David uses Minnie's example to muse that women are often cruelest to other women who break social rules. At the same time, women are softer-hearted than men, and feel worst about people in need, like Emily and Martha Endell. About Minnie's tough response to Martha Endell and Emily, Mr. Omer comments: "Young women are contradictory creatures [...] but their hearts are soft and kind" (51.80). Mr. Omer is sure that Minnie's harsh words about fallen women are all a show, and that Minnie would be kind to Martha Endell in private. (We'll be talking about morality and sympathy a bit more in our theme on "Gender.")