What is the ruling of Islamic law regarding an 'urfi marriage without witnesses to a woman whose divorce from her previous husband has not yet been finalized, and what should be done about it?

A Muslim is not permitted to undertake an action before consulting scholars, especially concerning matters of marriage. If a Kitābī woman embraces Islam and her husband is Muslim, she remains married to him until separation by divorce or khul‘ (dissolution of marriage initiated by the wife). If her waiting period ('iddah) ends, she may marry another man. However, if her husband is a disbeliever and remains so, her marriage to him is annulled. If her waiting period ('iddah) ends before he embraces Islam, she may marry another man. A Muslim must avoid legal complications if she is still legally married. For a marriage to be valid, the presence of a guardian (walī) and two just witnesses is required. A mere agreement between a man and a woman is not a marriage; rather, it is zina (unlawful sexual intercourse), and whoever commits it must repent. If a Muslim woman does not have a Muslim guardian, the responsibility of arranging her marriage falls to the authority in charge of Muslim affairs, such as Islamic centers, or she may delegate a just Muslim man.