Is a wife considered sinful if she does not feel happy with her second husband and still thinks of her first husband, which affects her marital relationship, and is there a solution to overcome this feeling?

A woman must obey her husband, and among the most obligatory rights is responding to his call to bed. Severe warnings are directed at the wife who refuses. As for her love for her first husband and her inability to forget him, there is no sin in it as long as it is merely a thought in the heart. However, she will be held accountable for any negligence in her husband's rights resulting from it. It is advised to pray and resort to Allah to get rid of these thoughts that harm her religious and worldly affairs.