Don't count on anything to happen just from noting on your reservation that there is a special occasion. You could get free food and cards, a window seat, etc, but nothing is guaranteed beyond well wishes. If you want to make sure she receives something, you'd need to arrange and pay for it by ordering a cake or floral arrangement or something. As far as I know, you cannot buy a window seat or a fireworks view. If you don't end up with one, you can go outside to the observation deck to watch and ask to have a gift or cake that you've arranged for delivered to the table while you are gone, that sort of thing.