Hello, I wish you had explained some incidences where your sister feels scared. It is possible that your sister is suffering from some phobia. Phobia is irrational and excessive fear of something that is usually not fearsome. For example, if I am too much scared of being enclosed into space like elevator, I have claustrophobia, while getting into elevator is very simple for others. The same might be true for your sister. When you talk with her, she feels better meaning counselling can work for her. You can make a note of day, time, event and things associated with fear when your sister feels scared. You can also note down how she could calm down.Following these notes, you can recognize a pattern that can guide you to thing or event that makes her scared. If you talk calmly and patiently with her, she herself might tell you what scares her. You can work with her to eliminate this phobia by counselling, motivation and giving her support. If you cannot make her feel comfortable, you can take her to a psychiatrist or mental health professional. They can do the counselling session and figure out what phobia she is having. They can give more counselling sessions, prescription medicines and/or behavioral modification therapy that can divert her fears into some other energy that is not harmful. I hope this information helps. Thank you for choosing HealthCareMagic. I wish you can find solution of your sister s phobia soon. Best, Dr. Viraj Shah