What is the ruling on a woman acting as a judge, and is it permissible for her to issue a ruling while she is menstruating, and is it permissible for a woman to act on behalf of the guardian in marriage?

It is not permissible for a woman to hold the position of a judge, according to the majority of scholars, due to the condition of masculinity for a judge. They cite the hadith: "A people will not prosper who appoint a woman to govern them," and because leadership positions should be held by competent men. However, Abu Hanifa permitted a woman to be a judge in matters of finance only. The guardianship of a female in marriage is not valid according to the majority of scholars.