Is the marriage that took place between the questioner and his maternal uncle, through offer and acceptance over the phone for the marriage of his six-year-old daughter, considered a valid marriage? Does divorce occur by saying "your daughter is divorced" after informing two men of that? Is it permissible for the questioner to marry the child's grandmother or mother based on what happened?

The maternal uncle's statement, "I marry my daughter to you," is a valid offer (ījāb). However, your saying "I agree" is not a valid acceptance (qabūl) according to the Shāfiʿī school and those who concur with them, as acceptance must be with the word for marriage (nikāḥ) or marrying (tazwīj). Furthermore, the contract was concluded without two witnesses, and among the conditions for the validity of marriage is the presence of two witnesses, based on the Prophet's (peace be upon him) saying: "There is no marriage except with a guardian and two just witnesses." Therefore, this marriage is invalid, and the rulings of a valid marriage do not apply to it.