hristi,
I think you are very talented and although Disney may have copyright to "their" images & characters They don't have copyright to yours- They can't stop you from your talent! Unless you sold them posing as a "Licensed Disney Artist" - IMO you should have carte blanche- WTG btw! They are gorgeous- What wonderful gifts they would make also!
But on the legal note- I would do some copyright searches in general to really read what constitutes the rights you have, against the images you are drawing and the fact that the designs themselves are probably copyright by Disney Designers, archtitechts (sp), planners, Imagineers, etc- Just so you have some type of info on it- I do know that archtitechts do have designs copyright-ed so no one can design the same w/o their permission- etc