In Ngugi wa Thiong'o's Petals of Blood, Wanja is pregnant by the end of the novel, and this is a pregnancy she has long desired. Let's look at this in more detail.

Wanja has had a child before with a rich businessman named Kimeria. She was very young then and disowned by her family. She left the child she bore to die out of despair, but she has always grieved over that. She desperately wants another child, perhaps hoping to make up for what she has done in the past. Finally, she becomes pregnant. The father is likely Abdulla, whom Wanja has come to regard as a real companion. This baby, she seems to think, will give her a second chance to be a mother.

Yes, Abdulla is indeed missing a leg due to his involvement in the Mau Mau Rebellion. Wanja considers him a hero, but he is largely forgotten by the world otherwise, left to try to scrap by as a bar owner and shopkeeper. The contrast between his past and his present is sharp and sometimes painful.