Hi thank you for using health care magic. I can understand your concern about your sister. It look like your sister has hearing of voices as well as ideas or delusion of reference. This are the sign/symptoms of a psychotic disorder. Most possible diagnosis is schizophrenia/schizophreniform disorder according to the duration of symptoms. Other less likely possibility is bipolar mood disorder manic phase. Consult a psychiatrist as patient interview is needed for accurate diagnosis. There is proper treatment available for these disorders and patient can live good quality of life with medicines. Hope this will help you. Thank you.