When did she start believing in herself?

When Maya returns to Stamps, somewhat broken following her molestation, Bertha Flowers takes her under her wing. Maya is entranced by Bertha, and her formal education. Bertha teaches Maya to speak again, using language not only as a tool, but as a weapon when she needs it. She explained that even though her people were "homely," their knowledge was vast and highly valued. It was Bertha who taught Maya that her heritage was important and that her language was powerful. It was also Bertha who introduced Maya to poetry, an art form Maya would continue to practice throughout her life.