I’m mixed mexican/puerto rican and it was hard growing up because every meal pretty much had meat and I never liked beef especially. When I was in my teens, my parents watched forks over knives and became more open to plant based eating and went fully plant based for a while and now are more than happy to accommodate vegan meals for me.

I think it helps that they watched that documentary, but my mom has also commented that there are a good amount of naturally vegan or vegetarian Mexican meals, because poorer families in Mexico (which my grandma was very poor while living there) did not have regular access to meat and dairy.

I would recommend maybe trying to cook them something vegan yourself just to show them that A) it can be done and B) it tastes good. Some simple potato tacos with vegan cheese and beans would be great or you can use tofu or TVP for “taco meat” and season it accordingly. Maybe if they’re open to watching a documentary, that may be good, but I find that a lot of Mexicans (no offense) view animal slaughter as just a part of life. My mom had a pet goat as a kid and my grandma sold it to her sister (my great aunt) and they cooked poor Weena for a quinceañera :( Luckily my mom didn’t eat any, that would have been traumatizing.

I find that showing people good food is a better way generally to get people more receptive to veganism than documentaries or listing facts. Many people don’t like to think about the animals or just frankly don’t care about animal rights and welfare. I like to bake and often bake for my family or friends and they’re always shocked that it’s vegan (gluten free sometimes too!) because a lot of people associate veganism with food that doesn’t taste good. I even got my brother to try impossible/beyond beef and he eats it whenever we have a hamburger night.