Margot gave you excellent advice. That is exactly what I would do. Please give us an update to let us know what is happening with her.
Ghilly
Sorry your pup isn't well. My first question is has the pup had all her shots? Has she been wormed? Any chance she may have gotten into something that may be making her sick? Is she throwing up food or bile? I would withhold food for 24 hrs but make water available. Does she have diarrhea at all? Do you know how to take a rectal temp (with a rectal thermometer)? If she isn't better within 24 hrs and the vomiting continues or you notice any other symptoms, I would make an appt with the Vet to have her checked out.
Keep an eye on her. Obviously at her age she's more apt to get sick than a dog that has their immune system built up. Is she eating? Is she drinking? Is she going to the bathroom? When she throws up, is it just clear bile, or is she throwing food up? If she can't keep anything down, and she's not going to the bathroom--get her to the vet ASAP. If she's like this for more than a day or two, I'd get her to the vet then too. It could be anything from that she ate something that didn't agree with her and it'll pass, to obviously something more serious. My 8 yr. old rottie still has times that he just plain doesn't feel good.
Good luck!