What is the ruling on marrying a young woman who works as a prostitute after meeting her in a nightclub?

First, you must fear Allah and abandon places of sin and indecency, for fornication is one of the major sins. It is forbidden for a Muslim to marry a fornicatress until she repents sincerely and her righteousness becomes apparent, because a Muslim is commanded to choose a righteous wife. If she repents sincerely, then there is no objection to you marrying her, for repentance erases what came before it. However, you must immediately cut off your relationship with her until the marriage contract is concluded, because this relationship is forbidden. If you wish to marry her, contact her guardian, as there is no marriage without a guardian.