Faatimah bint Yahya , may Allah have mercy upon her, was a great Mujtahidah of the 9th Century. A Mujtahidah (which is the female conjugation for Mujtahid) is a scholar of great caliber who can deduce from the sources of Islamic law (texts from the Quran and the Sunnah). In turn they use these deductions to give rulings in accord with both the contemporary and individual needs of the society. For one to be given the title ‘Mujtahidah’, one must have knowledge on both the consensus and opposing views of the Companions, the Successors, and the leading Scholars of Fiqh and Mujtahidoon (plural of Mujtahid). Hence, to be a Mujtahidah was not a minor matter, but Faatimah bint Yahya, may Allah have mercy upon her, deserved it.
Such was her knowledge, that her father — who was also a great jurist with several students — would be questioned by Faatimah, may Allah have mercy upon her, regarding several Juristic issues. The great scholar Al-Shawkani, may Allah have mercy upon him, — says about her: ‘She was most famous for her knowledge. She had debates with her father on several juristic issues. Her father, the Imaam, confirmed that Faatimah, may Allah have mercy upon her, applied Ijtihaad in deriving rulings. This indicates that she was prominent in the knowledge, because the Imaam would not say something like that except for one who deserved it.’
Her father married her off to the scholar Al-Mutahhar ibn Muhammad ibn Sulaymaan ibn Muhammad, may Allah have mercy upon him, (d.879). Al-Mutahhar was very lucky since whenever he would be confused on a matter he would refer to his wife for judgement on difficult juristic issues. Even within the midst of his students, when he, may Allah have mercy upon him, would get stuck on a complicated issue, he would get up and head for the curtain, behind which the great Mujtahidah would be sitting and ask her.
When he would come back with the answer his students would say, ‘This is not from you. This is from behind the curtain.’