Some ideas:

1. Progress has many negative effects on Rigoberta Menchu and the Guatemalan people.
2. Rigoberta Menchu has written her autobiography as a means of bringing a better life to her people.
3. A strong work ethic is an important part of the triumph of the Guatemalan people in the novel.
4. Rigoberta Menchu struggles with traditions in this novel; sometimes clinging to them and sometimes eschewing them.

Check out the analysis of this novel right here on eNotes for some other ideas that you may find more interesting to write about.

What is a thesis statement for racism in I, Rigoberta Menchu: An Indian Woman In Guatemala?

Hi!  I haven't read this book, but I can help you come up with a good thesis statement.  Whenever you are looking at a book/topic for a paper, you need to make a list or several lists to help you organize your ideas.  First, what evidence is there of racism in this book?  What events happen or how are people treated?  Are the events or treatment justified in any way by characters in the book?  If so, how?  How do you feel about the examples of racism and/or the justifications of it in the novel?  Now that you have all of these answers, make sure that you make a statement about something that matters to you.  Don't try to write a paper about something just to meet the deadline...it almost always ends up being uninteresting and flat. Be sure to choose a topic that matters to you (if it's teacher assigned, play with it until you can see an angle that interests you).  Also, make sure that what you've written is a thesis--not a topic.  For example:  "Cats in apartments" is a topic.  "Cats make better apartment pets than dogs" is a thesis.  Now you can come up with 3 or more reasons WHY you believe cats make better apartment pets than dogs, and support each reason with anecdotes, quotes, research, or other means.

Good Luck!