What is the setting of Lilith's Brood by Octavia E. Butler?

When the story opens, the only setting that is seen for some time in the story is that of the isolation room that Lilith is kept in. Once she is allowed out of her room the space ship she is kept on is described. The space ship is actually a living thing and so much of the story explains how the ships work and what they are capable of. The way that a ship is grown is looked more closely at later in the story because there is another ship that is started growing on Earth. Although what Lilith is kept on is a ship, it is such a complete ecosystem that it is hard for many of the Humans to believe that it is actually a craft and that they are not on Earth.