Hi Debbie,
Yes, as Kaylee mentioned it definitley has to be worth mentioning at check-in, but they are limited in what they can do. So it may be worth asking to speak to the manager (LOU CARRIER) to commend him on such a great hotel so good infact, you come back to celebrate a 21st Birthday ! He is a really nice guy and he is definitley the person to make your stay special. If Lou Carrier isn't around, speak to Mark Shouger (Rooms Division Director), Direct line - 407 503 2150 about a possible room upgrade ( The Graceland suite looks good !).
The HR cafe would also be a great place to celebrate a 21st. If you go over there speak to Tina (general manager) and Terry Murphy (Operations manager) 407 351 7625. They will really help you out with any surprises you may want to plan, especially if you mention you have been there before. If you do plan to eat there, ask if you can see the Lennon room aswell.
Hope this helps
Paul