Thank you all. You've given me a lot to think about!
As far as her husband and girls nights, originally Bob started joining us when my husband had a complicated crafting project that required Bob's assistance - they'd eat with us then go outside for woodworking. Now Bob and my husband join us for dinner then disappear to the garage to mess around with armor or other crafts. So Bob is pretty much a non-issue other than Emily's insistence about food for him. Oddly Bob himself has said for me to just make whatever and that he wants to try and learn to like different foods, and seems mortified that Emily even told me about his food preferences and made a big deal out of them. Bob gets real quiet and looks embarrassed whenever Emily starts going off about foods, or he'll even speak up in my defense saying carbohydrates are part of a balanced diet.
As far as Emily - everybody brought up a lot of good points for me to think about. I hadn't thought of it this way before, but maybe she is using her food issues to control others. I know the panic attack in particular seemed very off - it happened while I was out of the room, my husband recently brought this up and gave me more details about it - he said she ate the truffle, seemed totally fine, then when I re-joined the group she immediately started the waterworks and said she had a panic attack. That makes me very uncomfortable, and when I think about it more it does seem like it could be an attempt to control not only what I serve but what foods I have in my house.
I haven't ever brought up her inappropriate behavior about food with her because she seemed so emotionally fragile after her diagnosis. She is trying to keep her whole diagnosis a secret because she's afraid somehow her mom, who she's estranged from, will find out and gloat because her mom always used the threat of diabetes to pick on Emily's weight. So she's got a whole bunch of emotionally issues wrapped up around this, and I figured I was in a much stronger place emotionally and could just suck it up and deal with her comments. But lately it's gotten to be too much, and this has been going on for about a year and now I've had enough.
I think for now I will start with messaging everyone with a menu ahead of time, and suggesting people feel free to bring something if they have an issue with it, and play dumb if she complains. I'm also going to cut back on hosting these things to once a month, because you all are right, it is just not fun anymore as things are right now.
I hadn't realized just how bad it all was, and how manipulative she comes across as til I've read everybody's responses. She really isn't like this about other things, but food seems to be the outlet for all of her anxiety issues, control issues, and insecurities I guess. But I just can't keep being her emotional punching bag about it.