Is it permissible for a girl to leave her fiancé, who has not yet consummated the marriage, despite her love for another person with whom she has only recently spoken, knowing that her engagement took place under family pressure?

Your meeting with the married woman is forbidden and is one of the grave sins that falls under the warning mentioned in the Prophet’s (peace be upon him) saying: “He is not of us who incites a woman against her husband.” This act is one of the greatest forbidden acts, and among the actions of devils by which one of them seeks closeness to Iblis by separating a man from his wife. So, you must cut off your relationship with her and repent to Allah, and He will compensate you with someone better than her. If she is divorced for a reason other than from you, then you must approach her guardian to propose to her.