As others mentioned, they do rotate, and no one is guarenteed(I think Belle usually does the photo at beginning, but have heard of Aurora doing it as well). I had always heard about her being there for dinner, but didn't want Norwegian food, but have heard a lot of reports about her appearing for brft lately, and am hoping to see her in a few weeks w/ my DD(in her "human" form!). However, if she's not at your meal, you can see her in the Grotto in Fantasyland in MK, just try to go early (opens at 10:00)-lines will be 60 min all day. We met her here in her fins - she does spend time w/the kids when they reach her, and there is a water play area for the kids while you wait(bring a swimsuit), so it is not too bad. And you can check all the other princesses you meet off the list for photos/auto., which saves time & waiting in line in parks later. Enjoy!
ps-I will post when I return & let you know if we saw her!
cassie58
11/08-ASMo & Timeshare
8/09-CSR