I am not entirely convinced V has a firm gender identity. Inkyrius looks physically male, but that proves nothing. However, overall, V, to me, seems female. The fact 'she' rooms with Haley, the balance it maintains between the OotStick and the OotScribble, and the sheer level of vengeance V feels 'she' must enact against the ABD. Mama bear is a scary thing, and I think the DarthV arc was a shining example of exactly that.