5'6" is Pluto height, so you can do Pluto and some other characters.
I think that might be too tall to be a Princess though, I think Princesses top out at 5'5", but I'm really not positive as I really didn't deal with Princesses as a costuming CM.
Yeah, it's all about height. I found that I'm a terrible height for Disney. I'm 5'9", which there are only a handful of characters that are in that range (not that I'd ever want to be a performer anyway), but it's all about height.
And then besides height, for face characters, it's about face, coloring, weight, clear skin, and 500 other things you'll never know about.