وعليكم السلام ورحمة الله وبركاته

Sheikh ibn Baz rahimahullah was asked a similar question. He said (paraphrasing): Prayer in congregation is an obligation specific to men. If women gather in a place, it is not obligatory for them to pray in congregation, rather each one can pray alone and there is nothing wrong with that. But if they pray in congregation and one of them leads them, this is fine. The woman who is leading them should stand in the middle of the row, and she shouldn't stand at the front like a man. She raises her voice with the takbeer and so one, so the others can follow her. NOTE: In the above case where women are gathered together in one room, it's better for them to pray in congregation rather than praying alone, due to the general evidences proving that congregational prayers are better. The Lajnah Ad-dai'imah gave a similar Fatwa (8/213).