Hi Silvia!
I think the breakfast with the princesses that you are referring to is Cinderella's Royal Table at Cinderella Castle in Magic Kingdom theme park. This is a truly magical experience for little princesses to enjoy - they not only have the chance to dine in the castle, but also enjoy meeting some Disney Princesses, who will visit your table during your meal for photos and autographs. Full details can be found
here.
This is a very popular character dining experience, and does become booked up very quickly. Advance dining reservations can be made up to 180 days prior to your visit, and when your date becomes available you can book online
here, or you can call to make your reservation (407) 939 3463.
An alternative opportunity to dine with the princesses can be found at Akershus Royal Banquet Hall which is located in the Norway Pavilion in the World Showcase at Epcot theme park. For more details, see
here. Reservations can be made using the same links above.
I hope you all enjoy a magical time with the Disney Princesses!