Try checking out the Chiari Malformation Forum; it is very informative. These shunt malformations have been discussed alot in that forum. I hope that helps you. I have no knowledge about them, sorry.
The best always.
Thank you for your question. Although without being able to examine her I can not offer you the specific advice on diagnosis and treatment that she needs, but I would try to provide you some relevant information about her health concern.
If she has continuous symptoms, possible causes may be shunt is either under-draining or over-draining. Her doctor can assess this with a lumbar puncture and measures the fluid pressure. He or She may make some adjustment of the shunt to allow it to drain more and can monitor if the symptoms improve. Another possibility could be shunt is over-draining, that may lead to low CSF pressure that can also lead to headache. This may improve when the person lies down and gets worse when the person sits or stands. Please arrange an appointment with a neurologist right away who will evaluate the further underlying disorders here that may be the main reasons of her symptoms and can suggest her appropriate treatment. Hope this information proves helpful to you.