DO everything ELiza said - she is absolutely correct. I would add to examine all of your houseplants as well.
Some dogs need severaal small meals a day, or they have stomach upset - discuss this with your vet (there is no harm in splitting up meals for now anyway) - but also if she throws up again today, get her looked at right away. WHile it can be just a sensitive stomach and possible allergy, it can also be an indication that she has an intestinal blockage from eating something she shouldn't. At least call your vet, even if you don't go in.