Hi, The symptoms sound to be severe. As per the details provided by you your sister could be showing signs of either depression, anxiety or schizophrenia. However, let me add that the details are still a bit vague and some more information would definitely help for accurate diagnosis. Please do get her checked by a psychiatrist asap.

Hello.. Well is she undergoing some sort of stress? It's quite possible because of the lack of attention from husband also... Better consult a psychiatrist first