Super Yellow Leaves in Mid/Late Flower

From every seed, you get a different plant, if you want them all to looks the same you need to take clones. She probably has just stopped intaking nitrogen, the greener one may still be intaking it but will eventually stop aswell. The reason why the smaller ones are still greener is because they are smaller thus requiring less nitrogen, the bigger ones need more of it so they show the sings of lacking N more quickly. I wouldnt supplement with nitrogen at this point excluding the nitrogen in the bloom nutes, they usually have less nitrogen amounts specifically due to this, and that little ammount is enough for the plant, if she doesnt want to uptake it, then dont force her. :) Stay lit growmie. Best of luck.