Acknowledging that I wasn't there and she was, I would tend to disagree with your RN friend. When someone is vomiting it's best to give very small amounts of liquids by mouth. I mean very small...a teaspoon or two at a time, every 5 minutes or so. This fluid will generally not be a large enough volume to trigger the vomiting reflex, and will be absorbed directly from the stomach into the bloodstream. It's almost like giving an IV. 10ml (2 teaspoons) every 5 minutes is 120ml an hour, which is the maintenance fluid requirement for an average-size adult. It's a pain in the butt for both caretaker and patient, but it works. If you can get Pedialyte or another oral rehydration solution, so much the better, but the most important thing is water. (In your friend's defense, NPO -- nothing by mouth -- was standard treatment for a long time, but slow oral hydration is now the preferred form of therapy, at least, as far as I'm aware.)

Aloha,
Mark