Hi Tara,
I can't think of anywhere I would rather celebrate a birthday than at Walt Disney World!
You don't say how old your daughter is, so I will offer a couple of suggestions:-
1/ You could arrange for your daughter to be magically transformed into a Princess at the
Bibbidi Bobbidi Boutique beauty salon at either Cinderella's Castle in Magic Kingdom theme park or World of Disney Store at Downtown Disney.
2/ You could make an advanced dining reservation at a
Character meal and arrange for a specialty celebration cake which are available for an additional charge and should be ordered 48 hours in advance by calling 001 (407) 827-2253.
3/ You could purchase tickets to
Mickey's Not-So-Scary Halloween Party which is a special event which takes place at Magic Kingdom theme park on select nights during September & October. We love to attend this party which is a lot of fun for all the family.
I hope that this has given you some ideas but feel free to come back and ask another question if I can help with anything else.
Wishing you a magical holiday!