If this question refers to "Black Woman" by Georgia Douglas Johnson (published 1922 during the Harlem Renaissance), the two stanzas of this short poem explore the speaker’s fears for an unnamed black girl whose calls the speaker is reticent to respond to, only to reveal, at the end, that the speaker is pregnant with this "precious child." The ambiguity about the relationship between the speaker and the addressee makes room for this poem to explore messages of discouragement that are given to black girls, from the point of view of both the world that might deny her as well as the parent who yearns to protect her.
In the first stanza, the speaker’s repeated assertion that "I cannot let you in," combined with the opening line, "Don’t knock at my door," suggests that the speaker is inside her home and that the girl is knocking at the door to be allowed inside. This implication sits uneasily alongside the first stanza’s references to the sins of the world, indicating that the refusal to let the child in is a simultaneous—and morally uncomfortable—refusal to give her needed comfort and safety.
However, the second stanza uncovers a very different relationship between the characters. In the final lines, the speaker reveals herself to be pregnant with the little girl, exclaiming: "Be still, be still, my precious child, / I must not give you birth!" This shift implies that the "door" at which the girl has been knocking is the metaphorical door of the woman’s body as she comes closer to the moment of labor and birth. Rather than refusing the child’s need for shelter, the woman is actually fearful of having to release her from the shelter of her body, worried that she may later be compelled to deny the child’s call: “I cannot bear the pain / Of turning deaf-ear to your call / Time and time again!” In not wanting to let the child in, she appears not to want to let her out of the womb and into a world that her mother will be helpless to protect her from. The black woman named in the title is the speaker, who knows the dangers the world poses to black girls because she has been one herself.