This has happened twice before with goob in the last three years. The first time, goob was running and running, playing very hard and almost an hour later he had his breakfast. After about 20 minutes, he threw up ALL of his food. No bile. No foam. Just undigested kibble. He seemed to go right back to normal. I have him handfuls of chicken broth, chicken, and rice (no allergies) for the next few hours. I dont know if its true but I figured that if he threw up, the acids in his tummy were going crazy and I didnt want it to stay empty until dinner. He was fine and no more vomitting.
The second time, it was a very hot day and he wanted to follow us out front. We were sitting in the shade but it was still pretty hot. We came in, gave him breakfast and again, he threw up within 30 minutes or so. I did the same thing as before and he went right back to normal.
I can't say for SURE if it was the heat or if it was something else but since he went back to normal so quickly, I knew that it wasn't anything to be alarmed about.
I hope your girl is doing better.