Is the wife's consent to the marriage a condition for the witnesses to be heard, and must the witnesses be from among her mahram relatives or others?

The well-known opinion within the madhhab (school of thought) is that the witnesses to the marriage (nikah) must not be from the ascendants or descendants of the husband, nor the ascendants or descendants of the guardian (wali), nor the ascendants or descendants of the wife. As for the requirement of witnessing the wife's consent, there is a difference of opinion; the madhhab considers it sunnah (recommended) and not obligatory. However, due to the frequency of disputes, it is preferable for the witnesses to attest to the wife's permission. The wife must be present in person to give her permission for the marriage, and it is not valid for anyone to deputize on her behalf.