The old woman refuses to give up her books and then, rather than live without them in a repressed society, she lights the match that burns the books and burns herself with the books. She represents the people martyrs - people who believe in a cause to such depth, they are willing to die for their beliefs. The old woman believed in freedom and in books so much that she would die.  Before she dies, she cites this quote: "...we shall this day light such a candle,..., as I trust shall never be put out."  The meaning is that the act the woman is performing - burning herself up along with the books - will awaken people to her cause.  It is like lighting a candle in the dark illuminating the situation and illuminating that former darkness to such a degree that people will be moved to action that will forever change things for the better.