Gringa isn't such a bad thing
Gringa or Gringo is not always a derogatory term in Mexico. On my first day teaching English in Morelia, when my second-grade class found out that I from the United States they started giggling, laughing, and shouting "Gringa, Gringa!" I was embarrassed, thinking they were mocking me and that I had lost any control and authority in the class. Just then, the classroom teacher turned to me and said that the students were so excited because they never had a American (or native English speaker) teach them English before. Not only is Gringa (or "Gringo" for an American male) not a bad word, it is also a tasty taco-style dish!