Dogs do get viruses from time to time and these usually pass in 24 hours. With such a small breed you have to worry about a drop in blood sugar and dehydration from vomiting so make sure she is still drinking water. To raise the blood sugar put some pancake syrup along the gum line. I would try a bland diet of boiled chicken and white rice to help with stomach upset. If symptoms continue or get worse then I would have her seen.