What causes strange behaviour, incoherent speech, disorganized thinking, and amnesia?
Get her evaluated by a neurologist.
I have gone through your question and understand your concern.
There is a possibility of complex partial seizures.
Another possibility is psychiatric illness like delusion or schizophrenia.
You should get her examined and investigated by a doctor at the earliest.
Hope you found the answer helpful. Do get back to me for further information.
Dr. Neeraj Kumar