Autoflower lst query

So quick update and query, the girls blew up in size showing 2 different phenos one being a really pretty neon green, they both still need a few weeks but one already has older fan leaves going yellow. It looks like a nitrogen deficiency but they are currently going through flower so i know nitrogen levels should be lower at this stage, so im wondering if this is the natural process of things or if its deficient in something, pics to follow, cheers bros

So its nearly chop time so i thought id update with pics, the first pics are of the runt which smells so fruity right now, the other pics are the more sativa dominant pheno which has foxtailed hard, assuming it was due to genetics.