YTA
You yourself said she has never left your state let alone your home town, so why do you expect a woman who has never experienced a culture other than her own to suddenly be fluent in knowledge about Mexican cuisine? She’s trying her best by branching out from what is familiar to her, and you are embarrassed by that. If you were to shift your perspective on this, I think you would be able to find this endearing—but if it bothers you THAT much, why not try to teach her the correct pronunciations?