Is it permissible for the sister to seek divorce from her husband, who has not consummated the marriage with her for six years due to his financial circumstances, and to marry another man whom she desires and who desires her, while fearing that she might be unjust to her first husband?

If the sister has been lawfully contracted (married), it is not permissible for anyone other than her husband to propose to her, because she is under the marital bond of another man. Such a marriage would be considered invalid, and the suitor would be sinful. It is not permissible for a woman to seek divorce unless there is a legitimate Shariah reason. If she is harmed by the delay in consummation, she has the right to seek divorce. However, if the husband is righteous, he should be helped. But if it is merely an engagement, either party has the right to annul it, yet it is forbidden for a man to propose to a woman who is already engaged to another.