I'm not quite sure why Botana's was added as a veg-friendly restaurant as it is one of the least veg-friendly Mexican restaurants in Milwaukee. The menu says that only vegetable oil is used and not animal fat, but this refers only to the beans. The rice is made with chicken. The menu is gigantic but they only have one dish labeled as vegetarian, and that's cheese-stuffed peppers (be sure to not get the rice with it).
What I find annoying is that the default for all the dishes is meat, and not vegetarian to which one could add meat. Basically, you need to order and pay for a meat and cheese burrito but have it made without the meat and cheese (and without rice in some cases). I had a side of beans, which weren't bad, but didn't have much flavor (I think they're usually served with cheese). I also had the guacamole, which wasn't bad, but wasn't spectacular and didn't have much flavor.
The free chips and salsa are delicious and the service is excellent. Everyone is very friendly and attentive, they just don't have much to work with for vegetarians and vegans. La Fuente, down the street, is a safer bet, as they have a vegetarian section to their menu.