Hi thanks for your question.
Headache after lumber puncture (LP)is called as spinal headache.Occur usually after LP due to constant leak of CSF from subdural space and usually get resolved within 24 hours.However if your sister has developed headache at home after 5 days of LP, then it is not spinal headache and other reasons for headache should be sort.
Headache after LP usually responds to supne position, plenty of fluids,(some time intravenous are required) and caffeine.If these measure fail analgesics like paracetamol
are given and headache usually responds to alalgesics.
Finally if all measures fail epidural blood patch is given which seal the dural hole and result in complete relief in headache.
Hope I answerd your question.