It's got a lot of uses. I typically use beer as a coagulating agent when cooking meats, replacing the the same amount of milk, vinegar, or juice. The only thing you have to be careful with is the darker lagers may impart a bitter taste if cooked too long, due to the hops.
This use in a chili recipe is supposed to add complexity and flavor, if you notice the rest of this primitive's family seems to have liked it. She doesn't like beer and got a good whiff of it when she added it to the mix. Resonably, she was still thinking of the smell of taste and beer at the dinner table. That's a rather common response.
Beer can chicken is usually a good bet.