I just discovered that my fiancée committed Zina before we got engaged. Now she is saying she repented and she started praying. Now that my shock has passed, I am truthfully willing to keep her chaste and pure my Allaah reward me and forgive her and I. I feel like I need to know all about her past in order to get a correct opinion about her (in bad or good)… and make sure that she sincerely repented. Shall I tell her parents that their daughter committed Zina and that she's not virgin?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

If you are certain that the girl has repented sincerely then there is no harm in marrying her. Surely, Allaah will reward you the best for your intention to keep her chaste. Investigation of her past whether she committed other evils or not is not allowed. It is not allowed for her to inform her past sins since covering a Muslim's faults is among the great objectives of Islam. The Prophet said: "Everyone of my followers will be forgiven except those who openly expose their sins. Exposing sins includes a person disclosing ones own sin which was committed during the night and which Allaah had concealed it from the public, then he comes in the morning, and says, 'O so-and-so, I did such-and-such (evil) deed yesterday,' though he spent his night screened by his Lord (none knowing about his sin) and in the morning he removes Allaah's screen from himself." [Al-Bukhari and Muslim]

Therefore, you are not allowed to inform the family of the girl about her illegal sexual intercourse.

We entrust you, if you marry this girl, to help her in being steadfast and avoiding all kinds of sins like neglecting Islamic dress (Hijab), mixing with opposite sex or being alone with them and the like. Try your best to teach her the rulings of the religion and take her to the Islamic gatherings like Islamic lectures, symposium, etc.

Know that before completing the marriage contract she is marriageable for you so, so you are not allowed to be in seclusion with her, or to look at what is forbidden to be looked from her.

Allaah Knows best.