My 4 year old DD wore her Belle costume on formal night. We saw many little girls wearing their favorite princess ensembles!
To the little ones, wearing a pretty costume dress IS dressing up and they all look so cute too. My daughter insisted we call her Belle for the night. Our servers and the cast members were all so great to comply with her request! She had such fun being Belle for the night and we got a beautiful picture of her posing with Belle after our dinner.