I don’t know that it had anything at all to do with her being Hispanic. Sometimes a jerk is just a jerk.
I’ve never had any bad dealings with the mostly Hispanic fast food workers that I deal with here in Houston, but my mom and I did get one very cold reception from some black workers at a restaurant in Saginaw, MI. If you’ve never been to Saginaw, it’s very segregated and most of the motels are on the black side of town because that’s where I-75 is. My mom and I went to the Taco Bell down the street, and as we walked in the door, two black women in line gave us a look as though were invading their territory. Then, the black woman behind the counter never once gave us a friendly greeting or even smiled. Luckily, the food was all good. After that, we vowed to never stay in that city again.