Overwatering and deficiency

I'm not actually seeing a deficiency here - and am unclear what you are seeing that you think there is one?? First of all, let's clear something up - overwatering is NOT reflective of how much water you give at any one time - overwatering is the state of being constantly wet - so I don't think you've overwatered her... if anything, to me she looks a bit dry. If you're worried about the drooping leaves, that can be caused by too much nitrogen, under-watering and, yes, overwatering... but you can't overwater just once - it would have to be a constant thing. Personally, what I would do here is to give her a flush - give her 3x the pot volume of pH'd water (so in your case, you'd give her 9 gallons of water (see? this is NOT overwatering!!) and then let her dry out. When she's dry again, you can resume your nutes but at 1/2 strength for the first feed. After that, keep the grow nutes at 1/2 of what you've been giving while you take the bloom nutes back up to the level you've been giving them (in flowering stage, nitrogen needs to be cut back as it's not needed/wanted in the dosage required during veg). At this stage, you can also start adding a good PK boost... I use General Hydroponics KoolBloom liquid which has an NPK of 0-10-10 .... Good luck!