Just food for thought....i pretty much live by the rule and if we vomit, sweat, etc. that our body is rebelling against us and is trying to rid our body of something that it doesn't like or is not agreeing with us and is trying to get rid of whatever it is when we put something into it that is not a match for us. I would call the doc that gave her the meds and let them know what is happening because obviously her body is reacting in an adverse fashion.....good luck...........
Certainly the Symbicort may be affecting her. While she feels her heart, perhaps the anxiety of it gives her the feeling of nausea. This reaction can happen in a fraction of a second. It's possible she may have a stomach virus causing the vomiting. It's typical that your heart may beat stronger when vomiting, esp. if your blood sugar levels are down. Does she have issues with hypoglycemia? If the blood sugar goes down, it gives one feelings of anxiety, increased HR, arrhythmia, and feelings of nausea. But just to be properly diagnosed, your sister should be seen by a pediatrician for proper evaluation.