Sounds like either sinus drainage (from cold or allergies) with the mucus upsetting her stomach, or acid reflux (she lies down and the acid works its way back into the esophagus. If it's viral, I don't see how taking her into the pediatrician will help - there's no treatment. There are things you can do nutritionally to alleviate either problem - I'd be happy to help you with that. I would NOT go the route of reflux medications - I see SO many posts about that in MamaSource and MamaPedia - it's astounding how many doctors are throwing kids onto that stuff. I also read so much about people eliminating all kinds of foods from their diets to "solve" these problems but they are making themselves miserably through deprivation. I would say no to the cookies, as hard as that is. You could try flat ginger all, regular not diet. There is also a condition called hyperemesis which is basically a lot of throwing up that comes from not eating enough (which is caused by throwing up - I know, vicious circle) and the blood sugar level drops too low. Bland foods - you know, the "BRAT" diet of bananas, rice, applesauce, toast. Some turkey can be substituted for the "T" too. Small amounts of food throughout the day.
I just came from a nutritional conference and there is so much exciting stuff coming out of research, clinical trials and dietary changes with proper supplementation. It's so easy if you let the food scientists do the work - they know so much more than the doctors, who generally have no nutritional training. The good doctors will admit it though! My doctor and my husband's doctor are thrilled with what's happened for us. There were some great doctors and thousands of parents in the conference hall sharing what they had done for their kids - I'd be happy to share with you.