You are totall WRONG

You are totally wrong. You can say she is very stupid for doing this as an individual, but she is part of the Group --the Chinese group. When Others, such as native Americans, try to evaluate other Chinese, what she has done will definitely affect this evaluation, which is one of the famous attribution errors. You can not escape from it.
Sure you can boast your self-esteem, but what others see you is not only based on yourself, but on what they believe the Chinese are.

So next time, do not assume that small errors you committed will not affect others, Yes, they do. You are damage the image of all Chinese.