Grand Avenue is an honest glimpse into the lives of modern, urban Native Americans. After her husband's death, Mollie, a Pomo Indian, and her three children, Justine, Alice and Sheldon, leave their reservation home to start a new life in a Northern California city. They load their meager possessions into a battered station wagon and head to Santa Rosa, where clashes of culture and the pressures of urban life test their bond as a family. Mollie, Justine, and Alice fight their own individual battles against alcohol, teenage sexuality, and cultural identity. As the film progresses, each character undergoes transformation within a contemporary American society. .
Mollie, overwhelmed by the recent loss of her husband and the responsibility of being a single mother, drowns herself in despair and alcoholism. At the beginning of the film the audience views Mollie as a weak character who runs from her problems and usually ends up at a bar. In one scene, a Hispanic man hits on Mollie and calls her an Indian whore. Upset and enraged, she returns home drunk to her three children who are angered by her drunken display. In another scene when Mollie announces that she wants to move, Alice refuses and Mollie hits her, only to end up at a bar again. Mollie's transformation comes when she starts attending Alcoholic Anonymous meetings and meets a man named Sherman who expresses interest in her. Although Mollie is displayed as a character who is only happy when there is a man in her life, Sherman does help Mollie overcome her alcoholism and general rage towards life. Her complete transformation occurs when Justine dies. This shows that Mollie's life had to hit rock bottom before it could get better. In the scene at the end of the film when Steven and Mollie begin talking again, she tells him that the worse has happened, and asks, "What more could happen?" After Justine's death, Mollie becomes more of a mother who is calm and kind, rather than drunk and enraged like at the beginning of the film.