Sunni law bars women from leading men in mixed prayer

Evidence

In the majority Sunni tradition, just as women are prohibited from issuing the call to prayer or delivering the Friday sermon, they are also prohibited from leading men and women together in prayer (al-Jumal 1981, 12 1-26 ). All four juristic schools hold that men may only be led by a male imam. — Saba Mahmood, Politics of Piety, 610