Hi, it is good to know you care about your sister. You are worried about her. You mentioned that your sister has been having headache for four months, you can consult a doctor about this. It also looks like she could be stressed about something that is making her sit in one place and sleep. Do not worry too much your sister can consult a psychologist with whom she can explain about her condition. She can share about what she is going through with a psychologist She can consult a doctor first and then a psychologist.

Hello, Glad to know that you are seeking help,your narrative needs further clarification,as to which specialist you have consulted?Is headache getting worse?Has the doctor advised CT scan? It needs to be ruled out whether it is a tension type headache or miagraine.Is she stressed lately? Consult a Psychiatrist for further clarification.

It seems like your sister has been feeling down and gloomy for a few months and you're extremely concerned about her. I would like to take a moment to appreciate you asking this question, it's really sweet and caring for you to do so. Your sister is lucky to have you in her life. Stress, depression, anxiety, and other mental health conditions CAN cause physical symptoms like headaches. The constant headache and gloomy mood suggest that there could be a psychological reason behind it. I would recommend visiting a Psychologist to explore what's going on in her emotional life.