i dont have alot of experience with growing and i have no experience with cfl lighting, my first 2 widows were both grown from seed under a 600hps, up untill approx 3rd wk of flowering 1 was about 2 inches shorter than the other both raised on the same diet, now the shorter plant is approx 3 inches taller than its sister,
i now have 2 more widows just gone into flower, both taken as cuttings from the same plant and again 1 is approx 2 inches shorter than the other.
you could always take it to the doc to get a polio shot.
i say give it a couple of weeks