Personally, I have no idea why anyone would grow at 12/12 from seed, you may as well speed things up and give her 18/6 and then switch to 12/12 when you are happy with her size. This would easily save you a minimum of 3-4 weeks of the whole cycle.
Since you are growing with such a limited light supply, I would just let her do her thing without any extra stresses, she is already under enough stress by only getting twelve hours of light and growing with an abnormal metabolism.
Cheers, Organoman.