Riding the Bus with My Sister (2005)

With a flourishing career as a photographer, New Yorker Rachel Simon seems to have it all. If only her private life ran so effortlessly. She's at risk of losing a boyfriend who wants a commitment, she's estranged from her mother Nona who abandoned the family years ago, and she's grown distant from her mentally challenged sister, Beth, who spends her days in purposeful routine: riding the buses in her middle-class Pennsylvania town. But when their father dies, leaving Beth alone, Rachel reluctantly returns to the sister to whom she was once so fiercely devoted for a reunion that will change their lives.