You should have no problem finding a princess.
Here are the places I have seen them before, excluding Dining of course

I am sure there are other places too, this is just our experience.
Magic Kingdom:
Ariel is in her Grotto
Belle: Toon Town Tent, also after her storytime
Cinderella: Main Street in the morning, in the Toon Town Tent
Jasmine: Toon Town Tent, Main Street, Adventure Land by the Carpet ride
Snow White: Toon Town Tent
Sleeping Beauty: Main Street, Toon Town Tent
Epcot:
Belle: in France by the garden
Cinderella: In a building neat the front of the park....I'd have to pull out a map to tell you what building but it had a character sign on it on the map.
Jasmine: again the building near the front, Morroco-I have seen here near the front of Morroco under a tent like structure and I have found her in a small room in the very back of Morroco.
Snow White: In Germany near the front
Off the top of my head those are the places I can remember.
I have heard you can find Sleeping Beauty and Cinderella also in France at times.
If you consider
Pocahontas a princess (which I do

) you can usually find her in Animal Kingdom. I have also seen her in Toon Town.
Have a great trip!
