Thanks for writing your query.
It is good that the CT scan
report of your mother is normal.
after head injury
is a common symptom. It can be a symptom of concussion injury
. In this, some chemical changes occur, which manifest as some symptoms, vomiting and nausea being one.
Other symptoms are persistent headache, confusion or irritability, loss of memory, seizures, seeing flashes of light, difficulty in maintaining the balance of the body.
If there is no internal injury, you donot need to worry. Ask her to take as much rest as possible. This will speed her recovery from symptoms. If the symptoms persists, consult a Neurophysician.
I hope this is helpful to you.