Is the wife entitled to prevent her husband from marrying another, knowing that Islam has permitted a man to marry up to four?

Relationships between young men and women outside the framework of legitimate marriage are not approved by Islam. If a man's heart becomes attached to a woman, he should propose to her guardian, and she remains a stranger to him until he contracts marriage with her. The criterion for choosing a spouse is religious commitment and good character. You have wasted years in an unlawful relationship and in choosing a husband not based on religious commitment and good character, which has led you to contemplate suicide. We advise you to make sincere repentance, turn to Allah, strengthen your connection with Him, learn matters of religion, choose righteous company, occupy your free time with beneficial activities, and supplicate for provision of a righteous husband. If marriage to this young man is not feasible, you must remove your attachment to him and cut all ties with him, for whoever fears Allah, He will make for him a way out and provide for him from sources he could never imagine. As for a wife preventing her husband from marrying a second wife, there is a difference of opinion on this. If she did not stipulate this to him, then she has no right to prevent him. If she did stipulate it to him, then he has the right to it, according to the preponderant opinion of the scholars.