Yup, two insane eaters, and one indescribably resistant to *all* suggestion. Yes, it's exhausting. She's 9 now, and it's better in many ways, but the basic characteristic is deeply, deeply rooted. Any visible attempt to get her to go direction A will result in immediate resistance to the death - regardless of whether she actually wants A. In school, we have learned that it's critical she has a teacher well versed in the art of subtly nudging DD in the right direction from behind, without DD realizing what's up. One truly fabulous teacher was a bust for DD, as the teacher was simply too direct in telling DD what she needed to do, so DD would dig in her heels on principle, every time. sigh.
So I've always done a lot of the kinds of things you describe. I still don't tell her to go to the bathroom before a long drive, I just announce that I'm going (and that I will get there first - which launches a race to beat me there whilst I try to capture squealing evading child). I announce what I am doing a lot, without an invite, and often she then wants to jump in. She, too, loves to cook and never, ever touches the resulting food. She'll plan and produce whole meals for us, and never taste them. But if I put something on my plate and don't offer it at all, every now and then she'll actually ask for a taste. It's maddening and time-consuming to be constantly trying to lure and nudge someone like this. But a whole lot faster and easier than trying to drag her there by force!
So, I guess no magic answers here, sorry Skepchick. But I feel for you.
