She has combed and brushed her night-dark hair, And bathed rose petal sweet, And drawn white gloves on her small brown hands, And white shoes on her feet.
Look at that: we've lost our quotation marks. That's because we've switched from dialogue to narration.
What we learn from the speaker is that the daughter is getting ready for church. In describing the child, Randall uses descriptive imagery to show her innocence and her race. These are really the only details we get about this character.
She's described figuratively as "rose petal sweet," dressed all in white. White clothing is often used as a symbol for purity, and flowers as a symbol of loveliness.
At the same time, we're told that the girl's hair is "night-dark." This metaphor shows how deeply dark her hair is, but at the same time it gives us a clue that something ominous may be headed our way (after all, night is usually the time when bad things go down).