hi..tablet gardinal [phenobarbitone] is used to treat different types of epilepsy. if she was having epilepsy, and the treatment has control the fits then medications shud b stopped after 3 years of last episode of the fits.. you have not described the symptoms, but if she does not have generalized tonic clonic [strong contractions of the limbs and then gross movement of the whole body associated with uprolling of the eyeball, unconsciousness for 5 minutes, confusion for sometime and urination during the fit] movements then she does not need to start this medication again. there are possibilities that the behavior disturbances u are complaining are part of her confusion following seizure or it may be because of the psychiatric illnesse commonly seen in epileptic patients like, post ictal confusion, interictal psychosis like schizophreniform psychosis, personality problems, Gastaut-Geschwind Syndrome etc..behavioral syndromes like, depression, anxiety, aggression can occur.. if it is a part of postictal confusion then it can be improved with control of the seizures but here she does not have visible seizure..so there no chances that we can give meds blindly.. investigations like ,EEG, CT SCAN HEAD PLAIN, etc..shud be done if not done previously... so it is difficult to identify the exact cause without proper evaluation, she shud be taken to the neuropsychiatrist at nimhans... giving meds blindly is of no use.. i hope this advice will be helpful to u..best luck..