Call the vet anyways, ask if you can do a payment plan or defer payment til next week. Your dog's health is most important right now, and vomiting can turn into very serious issues that just build onto costs. In 24 hours your dog can become severely dehydrated. So vet now, not later.
She could possibly have parvo. If you cannot afford to take her then just keep a close eye on her. If she gets to the point where she is not wanting to eat then you will have to forcefully feed her. it might sound harsh but it works.
Try feeding her a different kind of food .. something as bland as possible .. even fried hamburger and brown rice..see if she can keep that down..if so..then you know it's the food have previously been feeding her that is making her sick..Her stomach can't tolerate it. Food intolerance and food allergies are very .. I repeat .. VERY common.
First, pick up the water. No water for at least an hour after she vomits.. otherwise she will just keep making herself vomit and the problem looks much worse than it is. Try bland diet.. Boil, so the fat is removed, chicken, mix it 2:1 with rice, blend it if you have to in a food processor. And no milk. Even if that was true about the poison, antidote for one is worse for another. And milk is bad for dogs. They do not process the fat well, or the lactose.