BBQ etiquette??

My sister in law invited us and the rest of the immediate family (there’s 8 adults and the only kids are hers) for a bbq in a few weeks. We volunteered to take sides and a dessert to help.

We were just informed that we would need to pay for our portion of the meat but I feel like if you’re hosting the meat is your responsibility??

She’s been dishonest in the past when we’ve split the cost of things so I’m hesitant to do so for meat (which can be pricey) especially when we weren’t allowed to have a say in what we are eating or how it is cooked. I would rather do my own dinner and then get together than go to her bbq and pay for something when I may not even get to eat all of what I’ve paid for.

We are having a baby in a few months and money is tight as it is so I don’t want to be forking out money for a bbq that wasn’t even my idea.

The petty part of me then wants to charge her for any food she eats at my baby shower because I feel like that’s along the same lines. (I wouldn’t but I’d like to tell her that just to see how she reacts)