A Girl Named Disaster by Nancy Farmer

From chapters.ca:
Nhamo is an unloved, unwanted orphan. And rather than face a hateful marriage she decides to flee her Mozambique village. Alone for the first time in her twelve years she paddles upriver toward Zimbabwe in her canoe. She sees off hippo and crocodiles, narrowly escapes drowning and survives for months on an island with only baboons for company. As if this were not enough, she is conscious wherever she goes of the spirits crowding around her - the benign shade of her mother, and the witches and other destructive spirits who must constantly be appeased. Nhamo is a heroine of unquenchable courage. Her transition from half- starved wild child to a strong, independent young woman with a place in the modern world gives a tender, moving and warmhearted quality to an extraordinary adventure story.