Is it permissible to continue supplicating for God to return the fiancé after his marriage, or must one stop this supplication out of fear for his wife?

It is permissible for a girl to ask Allah to marry her to a specific person, even if he is married, as long as he is of good character and religious. However, care must be taken that the supplication does not imply causing separation between him and his wife. There is no objection to supplicating for this person if his righteousness and religious commitment are known, and Allah is near, answering the supplication of the supplicant. A person can supplicate to Allah for whatever good they desire in this world and the hereafter. Nevertheless, good lies in what Allah chooses; therefore, it is advisable to supplicate that Allah chooses for her what is good and righteous in this world and the hereafter, and that she be content with what Allah has allotted for her. If this person is destined for her, he will be her lot whether she supplicates for him or not.