I agree Critical. If she is essentially "relapsing" with her food issues here due to the crap being put in front of her that's a problem. And I'm quite sure the holidays are triggers for her addiction issues already let alonehaving the bad stuff laying in front of her. Speaking of which I know many alcoholics who have a lot of difficulty going to family events at holiday time because they are also usually big drinking events for families.
And like I said she is going to need to evaluate if these are actually her friends or if they are just hangers on trying to find ways to normalize their own behavior. If they can't respect her and her problems enough to at the very least plan a healthier eating holiday (which honestly wouldn't have killed them) then I certainly wouldn't consider them friends.
That being said I have many friends who are alcoholics and I would not dream of letting the liquor flow at an event just because it's their problem and not mine. I respect them and their want to facilitate their healthiest possible life not throw up more road blocks to their recovery. I also have many friends on diets and I will then bring healthier foods to pot lucks etc. to support their choices. That is what friends do.