Is the marriage that took place with the maternal uncle as guardian valid, and is the subsequent return of the wife after her verbal divorce by the ma'dhun (marriage official) marrying her to him again without documentation valid from a Sharia perspective, especially after giving birth to three children?

The guardian is a condition for the validity of marriage according to the majority of jurists, while Abu Hanifa holds that it is not a condition. If the marriage contract is concluded following Abu Hanifa's opinion, or if a long time has passed and the wife has given birth, then the marriage is valid. The woman's guardians in marriage are her 'asabah (her male relatives from her father's side); thus, the maternal uncle is not a guardian. If the marriage is invalid due to the absence of a condition, then divorce takes effect therein.