Why is Anne unable to join the other activists who are singing "We Shall Overcome" at the end of Coming of Age in Mississippi?

I had to pare the original question down a bit.  Anne's
characterization is fundamentally different than other Civil Rights Activists because of
a richness that allows a spirit of questioning to emerge.  Simply put, Anne is distinct
from other Civil Rights Activists singing "We Shall Overcome" because Anne is wondering
whether they will overcome.  Anne's understanding of the Civil Rights Movement is poised
between two ends.  On one level, Anne is fundamentally angered at White America for its
mistreatment and cruelty displayed towards African- Americans.  At the same time, she is
frustrated at the inertia that is present in the African- American community.  Whether
out of fear or simple stubbornness, she finds that the resistance to change in the Black
community arouses as much anger in her as the dislike she possesses towards White
aggressors.  In the end, Anne is a complex thinker and character to fully embrace the
idea that the cancer of racism might go unchecked because of both realities that cause
so much repugnance within her.  In this light, Anne is unable to join the other
activists in believing that all will be well and "we shall
overcome."