What is the ruling of Islamic law on a marriage that took place with the pronouncements of marriage, in the presence of witnesses, and with a known mahr, but was not documented in writing and the family was not aware of it?

If a girl marries without a wali (guardian), the marriage is invalid according to the majority of scholars. If you desire her as a wife, a valid contract must be concluded through her wali. If her guardians are unable to be present, they should delegate someone to conduct the marriage contract, or the wali can be the Muslim judge. If a Muslim judge is unavailable, then a just and trustworthy man can undertake her marriage with her permission.