She would get pretty sick if it were kennel cough and no way could you wait until the 1st to see the vet. I would think your vet would have known it was kennel cough since you have already had her checked over.
I'd be worried about her trachea. Collapsed tracheas are such a problem in toy breed dogs. I assume she came with a health guarantee. I'd make sure he thoroughly checks her trachea including xrays.
Here is some information on collapsed tracheas:
Collapsed Trachea in Dogs