Does it seem surprising that Félicité's voice is shrill? Why do you think this detail is included in her description?

It does seem surprising that Félicité's voice is shrill because that's usually not considered a pleasant attribute and the rest of her qualities seem admirable and pleasant. A shrill voice usually describes a person who is high strung and finicky. This definitely doesn't seem to be a good description of Félicité, but maybe Flaubert is trying to be more realistic than symbolic in her description. Isn't it really just the luck of the draw what a person's voice sounds like?