your plant will show preflowers when it is sexually mature, in 12/12 or not. Many people wait til they show before they put them into flowering. Saves space in the flower room. Usually its 6-8 weeks old. The better the environment, the better chance of it being female. From what I've read, when you have 4-6 plants together, one will usually be male. Although that is not always true, its natures way of ensuring survival of the species. Gl to you