personally i think that could be pruned alittle. lollipop the stems from the bottom , this will help with airflow below the canopy ( there are several videos online on how to do this) and also makes the plants focus on making the top colas bigger. in the past when i had grows going i used to lollipop at the end of week 1 of 12/12 and at the end of week 3 . also u might want to thin the canopy alittle to allow more light to the lower bud sites. i never pruned alot at one time more like just a few leaves here and there every couple of days not to stress them too much. a general rule of thumb for pruning is only to remover older growth i.e leaves that stalks have a redish tint to them. anyways these are my personal views and methods that i have used with success in the past. Youtube has some great videos on pruning and lollipopping , its worthwhile to go have a look. your doing a great job for your 1st grow and u will reap the rewards for that :P

I hope this helps

Hal