Is the aforementioned marriage Islamically valid, and did the divorce become an irreversible major divorce based on the revocations and divorces that occurred?

A valid Islamic marriage has conditions and pillars, including the guardian (wali) and witnesses. The majority of jurists stipulate the presence of two witnesses for the marriage to be valid. If the marriage took place with only one witness and without publicizing it, then the divorce in such a case is an irrevocable divorce (طلاق بائن), meaning the husband does not have the right to take her back. Al-Mardawi said: "Divorce occurs in a marriage about which there is disagreement, such as a marriage without a guardian according to our companions... Two benefits: First: wherever we say that divorce occurs in it, it is an irrevocable divorce." Accordingly, the woman became irrevocably separated from the man by his first divorce. He is permitted to marry her again with a new contract that fulfills all the pillars and conditions.