What is the ruling on marrying a young woman whose character was not originally religious, but then she became guided and committed?

You must cut off your relationship and friendship with this girl, even if it is with the intention of marriage, because it is not permissible. A Muslim should choose a wife characterized by religiousness and good character, as the Prophet, peace and blessings be upon him, said: "A woman is married for four reasons: for her wealth, for her lineage, for her beauty, and for her religion. So choose the religious woman, and you will prosper." If the girl repents sincerely and adheres to the rulings of the Sharia, then there is no harm in marrying her, while continuing to advise her and urge her to repent and seek forgiveness.