This quote comes in Chapter Six, and is uttered by Ekwefi, the wife of Okonkwo, concerning her daughter, Ezinma, to Chielo. This is later explored in Chapter Nine, which narrates the trouble Ekwefi has had in bearing children that survive. A medicine man tells her that she bears ogbanje children, who are wicked children that die and enter their mother's womb again. The medicine man mutilates the body of her next child that dies, with the express purpose that this evil spirit will not return again:
Then he took it away to bury in the Evil Forest, holding it by the ankle and dragging it on the ground behind him. After such a treatment it would think twice before coming again, unless it was one of the stubborn ones who returned...
Thus the quote you refer to is talking about the spirit of Ezinma and whether she will live or not. It thus shows how superstitious and driven by witchcraft the lives of the Igbo people are, and what power such spirits have in their thinking.