Can the mother of the Greek Muslim girl or her brother-in-law act on behalf of the legal guardian in her marriage contract, given that her father is deceased and her paternal uncle is an alcoholic who refuses to marry her off?

A woman cannot be a wali (guardian) in marriage; rather, masculinity is a prerequisite. If a woman's wali (her paternal uncle) refuses to marry her to a suitable man without a legitimate Islamic reason, she may refer the matter to the Sharia (definition) judge or whoever acts in his stead, such as Islamic centers, because the ruler is the wali of one who has no wali. The jurists have stipulated that a group of upright Muslims can act in place of the ruler when he is absent. The transgression of the wali does not negate his guardianship in marriage.