3 Doctors agree with this answer
As you told, she needs love and security to overcime her lonliness,that can be provided by a partner or someone who can understand her in a better way and tender love and care for her. You should consider gettting a counseling done for her from a reputed counseller.
Hi.. She may need councelling and medical treatment.. I suggest she meets with a doctor in person.. A doctor or a councellor talking to her will benefit more than you talking to her.. I wish your sister recovers from the trauma...