thank you for information,
The nausea and vomitting along with abdomen pain may be associaated with some common causes like gastroenteritis, appendicitis, gall stones, intestinal obstruction, pacreatitis, etc.
As per the symptoms she should get the relevant investigations done like stool examination, sonography of abdomen, x-ray abdomen, liver function test after consulting the doctor/gastroenterologist to know the associated abnormality.
The treatment depends on the underlying cause.Meanwhile she may take the antinausea drugs like domperidone, reglan to control the symptoms.
The neurological causes like migraine, brain tumour etc should also be ruled out.
Here is the link for more informationcauses of nausea
Let me know if you have any doubt.