How plurality is expressed depends on the noun's case. This might help get your started: http://www.russianlessons.net/lessons/lesson11_main.php
Not wrong, but rather strange in English to use the definite article here, I'd say.
It's rather strange to be stating something obvious like: "You are women" in the first place, but even stranger to say: "You are the women."
We can't really know, without further context, but as none is given, better to leave it out, in my opinion - it certainly reads more naturally.