To what extent is the marriage of a Muslim woman legitimate, who claimed to have converted to Islam after her customary marriage to a minor, then divorced him over the phone, and married another man without the completion of the waiting period (iddah) required for her customary marriage, knowing that she now claims she actually embraced Islam during her last marriage?

If a woman is divorced after a valid seclusion (khalwa sahiha), she is obligated to observe the waiting period (iddah), according to the majority of jurists. The iddah for a menstruating woman is three menstrual cycles.

If the woman had three menstrual cycles since her (minor) husband divorced her, before she got married, then her marriage is valid.

However, if she got married before her iddah expired: her marriage is invalid (batil). But there is no sin upon them due to their ignorance, and the children are attributed to the husband. They must separate now, then she completes the iddah for the first (husband), then observes a new iddah for the second (husband). He may then marry her during this iddah with a valid contract.