Is this your Gorilla Cookies grow? I will assume that it is because some of the photos look similar (it's always good to start this question INSIDE the diary - you can find where to do that at the bottom of the page). Anyway, right off the top, I'm thinking you are not giving her enough water - .13 gals per day in a 5 gallon? That's pretty low - and what THAT says to me is that you are not flushing the nutrients you're providing her when you give her plain water so I think there is a build-up going on as well as perhaps some roots that are now dying because they haven't been getting the moisture they need.
I would advocate two things: get yourself some ReCharge (it reactivates microorganisms in the soil) and then give her the best drink she's ever had... I'd give her one gallon of ph'd water and then another gallon of ph'd water with 1/2 ReCharge in it (if you want, a tsp or two of molasses would also help) and then let her dry out completely. Underwatering, while fairly uncommon among growers (if anything, folks think that more water = bigger growth and they end up drowning their plants) just isn't good for the plant on any level. At her size, I would expect her to be going through at least 1/2 gallon a day - but she needs the root system to be able to drink it. When you feed her, make sure you get just a little runoff from your pot... when you water her, do the same but try for 10-20% runoff. Always wait until the pot is super light (which means it's dry) before giving her something else. And always, always, always make sure the pH is good (at her age, 6.2-6.3 would be ideal for all the nutrients she needs).
Good luck!