Yeah, there's some small preflowers on two or three of the newest nodes on the main stem...small thing looks similar to stipules with a small hair protruding..I'm about 87% sure that the biggest plant's female and the smaller one hasn't develped preflowers quite yet..

I've read that once you start 12/12, the plant grows somewhat rapidly at first, then begins to flower...How much more would my plants grow if I went ahead and went to 12/12?