what i'm getting from this is that it's an outdoor plant, and you bring it outside at 6 am, and outside at 8 pm? By my astute mathematical calculations, that is not 12 hours, it is in fact 14. Plants need 12 hours of light to begin flowering. Also, when you bring it in, the place needs to be completely black with adequate ventilation.
What i've read on here is that some people put double garbage black bags and put pin holes in the top one and keep the bottom one hole free but not all the way to the bottom of the surface.
What you could also do, since it is still vegging, is take a cutting and try to root it, and do the 12 hour in/out thing to it, just to find it's sex.
I don't have any experience doing this, since i don't have any height restrictions, but why not let mother nature take it from here?