What is the theme of the school days of an indian girl by Zitkala-sa

School days of Zitkala-Sa are hate and isolation, as she felt like an outsider in school among all those white people.

Explanation:

She is sharing her experience with white Americans and how hard she has tried to fit in. She is a representative of her people that were tortured trough history by white Americans. She had to pass a long path to be part of a different culture.