It is a serious case Tanu.I hope you have tried everything to convince her there is no spirit or ghost in the world or at least in her room by any chance.
If it is possible share your bed with your sister and let her know you are with her, and there is no ghost exists.
Try to change the room where she is sleeping.
If u did so, and found worthless, consult a psychiatrist who can help her. I wish she will be okay soon.
Please let me know abut her remedial process, time to time if u can, by blurbing.
Answered by
Subhro
, an ibibo Citizen,
at
4:34 PM on November 28, 2008