an amazing informative post from suhaibwebb.com
In his famous work Al-Isabah fee Tamyeez as-Sahabah, Imam ibn Hajar al-Asqalani reports on 1543 women scholars of Islamic Law, Hadith and Arabic literature!
As for teaching, the great granddaughter of the Prophet ﷺ Nafeesah bint al-Hasan was reported to have lectured to the masses in the Prophet's mosque as well as in Cairo. It is also well-documented that scholars like Ibn Taymiyyah, Ibn Hajar, Ibn al-Jawzi and Imam al-Thahabi were all taught by female scholars.
http://www.suhaibwebb.com/relationships/gender-relations/female-scholars-and-preachers-in-islam/