Overcomplicating things bro, leave them grow and the nitrogen in the soil is way enough for them small plants, definatly no ferts yet or messing with the soil, water light and right temps are all you need, thats how they got stunted in the first place.
This guy dosent have a nute deficiency whatsoever, those bottom leaves were damaged ages ago and have litte bearing on its general health now. New growth was getting better, i would have just left it as it was and watered when it needed then you will get more good growth. Seriously in that soil and those pots you arent lacking any nutes. I grow three time bigger plants in seedling soil which is much weaker without a single drop of ferts let alone nitrogen which is the biggest ingredient in most commercial soils these days and evenm the more marijuana orientated soils.
Dude you just got to leave them, trust that there are ferts already in the soil and your plant is in no way deficient, if anything you got these problems from adding too much ferts, water and messing around. Plant, soil water and simple. Even for a first time grower i recomend he not add ferts for a very long time until he realise that soil is feeding the plant for him, would have to get much bigger before ferts etc etc.
My advice is just water and let her grow, you will learn nothing by giving ferts at this stage and so much more by not giving ferts. In pots that big i could almost do a short grow with only having to fert once or twice for the whole time from seed to harvest. Miracle grow is strong soil too anyway, should have started in weaker seedling soil and that way you can start the ferts earlier and get more control.
Stop overcomplicating things, new growers mistake. Peace