family relationship question

Hi, I have a question about an inlaw. My sister in law offered to host family christmas dinner this year, instead of at inlaws. They have a pool and we thought it sounded great. However she just texted another sister in law to say no alcohol, the whole family will have a bqq and a couple beers or wines on Christmas day, we always have & I feel its alittle maybe deceitful? to offer her home for family function then impose rules. I also feel in general that we shouldn't impose our beliefs on others. So if you don't choose to drink alcohol, thats' cool, its your choice but you shouldn't force that onto others, in a passive or agressive way. We are all adults, its pretty australian to have a beer on christmas day for a lot of us, its certainly our family tradition, and while Im happy to respect her personal choice of no alcohol for her and my brother in law, Im not happy to have her foce that on me. The alcohol isn't the issue here. I can actually go without it lol, but its the principle that I feel she snuck this on us, that she tries to control the way we as a family do things, and that its enabling that if we let her. However its a tricky one as its now at "her home" and i usually think " your home, your rules" but in this case its a family dinner, and its a special occassion. So what do you think i should do? offer to host at mine instead whre people can bring whatever drinks and whatever meats they personally want? Talk to her about it, or just pretend i don't know (she texted another sister in law who then texted me to say "was she joking because I am pregnant") and bring my usual 6 pack of beer and an ssb? Thank you!