Take her to the Dr TODAY!
i personally wouldn't want to go on vacation if my child was sick - especially if you are going to Disney World - how much fun do you expect her to have when she's sick?
If she has an ear infection - you will be dealing with more than just a cold!! Especially if you put her on a flight and her ear drum bursts...i had that happen to me - and it was PAINFUL - seriously - giving birth was less painful than having my ear drum burst. Lost hearing too because of it.
While I love the Triamentic Cough tablets - it may not be what she needs. Putting her on a flight - well, again - I wouldn't. I think there are airlines that will work with you if you produce a note stating she was too ill to fly.
Bottom line - what kind of vacation are you going to have if your child is sick?