Answer:
Given this information, Julie's diagnosis would be brief psychotic disorder.
Step-by-step explanation:
Brief psychotic disorder may take place after a stressful or traumatic event. In the period of one day to one month, the person affected will present at least one psychotic symptom - delusion, hallucination, incoherence, catatonic behavior, etc. As we can see, Julie's case fits into that description. After a traumatic even (the loss of her sister), she showed a couple of psychotic symptoms (catatonic behavior and hallucinations). After a couple of weeks, she went back to her normal self.