We did lunch there on our last trip. I will say- it felt sooooo much more chaotic than CRT. In fact, that's my fear with us doing Akershus for breakfast on our upcoming trip. There were a lot of small children at both, but since the princesses take the kids around the restaurant at Akershus and it goes on for about 5 min, it might bother your mother if she's not up for tons of little princesses

. We were there for our girls and it was heaven to us, but it was a ton of kids parading around for a while.
As for Belle, she was there in her yellow dress when we went, but I've read a handful of stories about off days when Belle was not there. I've seen pics of days when Aurora or Ariel have taken her place. The odds of Belle being there are still in your favor.
As for food quality- it's a toss up. I liked my food better at CRT, but DH's food was better at Akershus. Of course, if you do CRT (and it sounds like you're doing
DDP), you're looking at 2 credits and if you get Belle there, you'll see her in her blue dress (I've heard the yellow dress is too big for the CRT dining room structure). Of course, CRT is a better bang for your buck to pay OOP...then again, not even sure if you're considering it as an alternative.