I'm not so sure. She got 13/100 in the second assignment, which means that she did it. If it was really such a big deal for her, why did she bother doing the alternative assignment at all? Wouldn't she just protest against it all the more?
No, I have a feeling that she didn't raise a fuss until she got the marks back. She is suggesting that her teacher is more interested in being Mexican than being American, and gave her a poor mark for not doing as she was asked the first time around. But the alternative assignment was specifically related to Mexico's independence, and so by completing the assignment properly, she would still be fulfilling her teacher's desire for her to learn about Mexico. Therefore, intentionally giving her a low mark as retaliation for refusing to do the original assignment doesn't really make much sense.
Something isn't right here. I suspect the student submitted her assignment, didn't like the mark she got, and when she challenged the result and the school did not accept it, she went to the media.