Looking for answers about concussion in child
 

My daughter sustained a concussion a little over a week ago during a mishap on a tire swing. She was seen twice in the past week at emergency rooms and several dr visits.
She has no complaint of headaches, dizziness or balance problems, no symptoms that you would think would be concussion related.
Her problem is that she has been nauseated since that day. We had ct scans, abd xrays, bloodwork, urinalysis. All came back normal.
She is sleeping well, and does seem fatigued, but I initially chalked that up to the nausea. You just cannot throw up like she has and not be tired.
Her nausea seems to be easiing a bit, but when it hits her, she is running for the bathroom. She missed school all last week, returned yesterday, had a good day, but then woke up this morning sick again. Obv we are not going to school today.
No other symptoms. No fever. No diarrhea. No headaches. No chills. Nothing. Just this persistant nausea and vomiting.
The dr's seem to think its just left over "stuff" from her concussion.
I have read about all I can get my hands on about post concussion syndrome, but sometimes I feel the internet can be an overwhelming thing and question, sometimes, it's validity. (you read many reports from many ppl, who do you trust?)
Thats why Im here. My thinking is, "ask ppl who have been thru it".
Has anyone heard of continued nausea and vomiting from a concussion? Again, nothing showed up on any of her scans. And she has no other symptoms but the tummy stuff. And she has good days, where she has been back to her old self, then it hits her like a freight train and she is down again.
Any input would be appreciated.