Hello, I am Dr. Coldiron and I will attempt to answer your question regarding your dog. Based on the info you provided it does sound like acid reflux...we call it gastritis in the dog. Basically the stomach becomes irritated and inflamed for whatever reason and dogs will vomit up bile (the yellowish fluid you mentioned). You may give her a Tums or Rolaids by mouth. Even better would be a Pepsid AC tablet (1/2 tablet twice daily for 7 days). I would recommend that you withhold food for 24 hours. Allow water consumption only...I know, she is going to look at you like your crazy, but hold off the food for 24 hours. Give only the water and antacids. If the vomiting continues or she starts to have diarrhea, you should get her to your vet as this can result in dehydration quickly.
P.S. You can give the antacid (Rolaids or Tums) twice daily for about 3 days!