I hope she is OK and it was nothing more than a bad tummy upset.
My usual rule-of-thumb is that it's quite normal for a dog to vomit, once, or even twice, but if a dog vomits more than twice in quick succession, there may be something quite wrong. More than twice -and I take mine to the vet.
6 times does mean there's a problem of one kind or another.
Dehydration is something to be aware of. Continual vomiting and no water intake, or inability to keep water down -and dehydration will start quite quickly.
YES she could be dehydrated or have lung cancer thats what happen to my dog and when we found out he had lung cancer we had to have him put to get her in ASAP
marksme is right, it isn't uncommon for dogs to eat things that will make them ill and not energetic. Take the poor girl to a vet, and they should be able to figure it out. Good luck = )
Sounds like she got a hold of something that made her sick, but yes take her to the vet asap!! Remember all your dog has is you!