Who has the right to determine the deferred dower, and can the husband's guardian be delegated to do so?

The prompt and deferred dowry is an exclusive right of the woman, determined by the husband or his representative, and the wife or her guardian. If the wife is legally incompetent due to minority or imprudence, her guardian is not permitted to accept less than her customary dowry (Mahr al-Mithl). If the husband is legally incompetent, his guardian is not permitted to accept more than the customary dowry. However, if both spouses are mature and of sound judgment, whatever dowry they agree upon is permissible, whether it is small or large. If the woman agrees to less than her customary dowry, her guardians have no right to object. Furthermore, it is permissible for the spouses to delegate the determination of the dowry to another party, and scholars have unanimously agreed on the permissibility of marriage by delegation (Nikah (definition) al-Tafweed).