OK--we are back from vacation and survived! There were moments where I swear to God my MIL reads these posts and has me pegged. She didn't bother me all that much--my DH, however, felt like HE was on the firing line, walking on egg shells. He was the one who couldn't wait to hightail it to our timeshare and be with his little family. Alone. He admitted his mother was driving him crazy.
MIL wasn't too bad with me. She noticed that my daughter was more distant after a few dirty looks about her food choices (though that wasn't it). Her negativity was pretty much shared across the board for all her kids and inlaws. The only one she seemed to like was a-hole step-bro-inlaw's current paramour. I made a point of saying that the reason they all still get along is it's a long distance relationship. OK, it was after a couple glasses of wine (they would give dirty looks, but kept pouring!), but I got my point across.
I did find entries to make some comments about relationships with ILs and regrets of which I've had a few. We shall see....