Is a marriage contracted without a guardian (wali) or witnesses, but with the father's knowledge and consent, valid in Islamic law? And what must be done if it is not valid?

The majority of scholars stipulate the presence of a guardian (wali) and two witnesses for the validity of a marriage contract. It is not sufficient for the guardian to merely know and consent; he must directly participate in the contract or delegate someone else. If a woman contracts her own marriage, or contracts the marriage of another, whether with or without the guardian's permission, the contract is void.

Some scholars have permitted a mature woman to contract her own marriage, but they have stipulated the presence of witnesses to the contract. A marriage contract is not valid with only one witness.

Therefore, if the contract was concluded without a guardian and with only one witness, it is void. Its rectification requires an offer and acceptance between your guardian and your husband in the presence of two witnesses. There is no need to re-document the contract. The child is legitimately attributed to his father as long as you both believed the marriage to be valid.