As far as Islamic Shari`ah is concerned, a male imam or teacher is allowed to teach women while sitting in front of them with no barrier, as long as there are no chances of any one of them and the imam being in isolation (khulwah), and they are abiding by the Islamic ethics of interaction between men and women.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states the following: If it is a mixed class of both men and women and there is no indiscriminate mixing and mingling between the sexes, there is nothing wrong with that. Likewise, if it is a group of women and there are no chances of any one of them and the imam or the teacher being in isolation, then again it is considered permissible — provided they are abiding by the Islamic ethics of interaction between men and women. We have precedents for this in the authentic practice of the Prophet (peace and blessings be upon him) as well as his Companions (may Allah be pleased with them all). We learn from traditions that the Prophet (peace and blessings be upon him) used to address men and women in mixed gatherings. He also used to teach women when they were in their own quarters; he was accompanied by Bilal (may Allah be pleased with him). It is worth remembering that Allah did not prescribe segregation of males from females in the Qur’an; He only forbade indiscriminate mingling and mixing and unlawful isolation. As long as none of these is happening, it is considered lawful for a male teacher or imam to teach women. May Allah help us to see truth as truth and to follow it; may He help us to see error as error and help us to shun it. Ameen.