If you mean to ask whether your sister has rights over a man she was in an illicit relationship, the answer is no. Unless he owes him money or other financial obligations, in which case, he certainly owes her.

 

Other than that, if he promised her something, if he is a Muslim he ought to honor his pledge.

 

If the promise is lawful surely, he will be accountable before Allah for as Muslims we are bound to fulfill the promises we make.

 

Having said this, if the brother is not fulfilling, then the sister should simply let that chapter closed and move on with her life; she shouldn’t waste her life waiting for him to knock at her door. He has already told her to forget him! So, she should leave him alone, and move on with her life – to preserve her dignity and honor.

 

Perhaps she needs to seek professional counseling if she is experiencing depression because of this sad experience.

 

Depression sometimes can be fatal unless treated.

 

Almighty Allah knows best.