Did you have the light that high from the beginning? Also those look to be sativa dominant, I would squat that light down considerably and start flowering when they are under a foot tall, prune all the lower branches off.. When growing indoors its best to keep the plant manageable so your light gets the best penetration possible..
Best of luck, this is all part of your learning curve..
Look for a good indica strain ie snow white, bubbilicous, ww (get a white strain to start with would be my suggestion).. try growing only the cola and a few top branches, prune them while they are in veg or early flowering.. That energy will get sent to the top portion of your girls, the light penetration to the lower branches is too minimal and sucks the energy from the rest of the plant..
Thats how I do it anyways, others may suggest otherwise..