ive grown out alot of males recently and only have three females left out of like twelve plants. cold killed a few but most just turned out to be male. the only thing you can do is examine the plant,see how tight the internodes are spaced ,or how thick the stem was, and how dark and strong the fan leaves were and hope for all of that in your next plants aswell and maybe you will get lucky. once you have a female ,establish a mother plant to take clones off of so you dont waste time and space growing males. i am currently vegging a clone to be my first mother plant.well, beside the one that the clone came from but shes flowering now.