Riding the Bus with my Sister by Rachel Simon

Subtitle: A True Life Journey -- This was a very interesting story about a woman, Beth, who has mental retardation, and what her life if like through her Rachel's eyes.  Through a long series of events Beth does live on her own, and what she does with her time is ride the city buses.  She asks her sister to join her for a year.  It is a very trying time for Rachel and she is put to the test mentally and emotionally a lot.  Along the way she learns about her sister's world, the people she knows and how valuable her sister is to her.  It is frustrating, maddening and very touching.