Well in Week 5 of Flowr they may yellowing.. its absolutely ok.... She just cannibalised herself for alittle nitrogen, Because she still ned small amounts of it... But dont worry.this way she took it out of the leaves. The plant concentrates now in flower. So in your next Grow give her up to week 2 in flower the full range of nitrogen like before and after week 2 less. Iam sure you have a feeding schedule from flora bloom....( wich company is that..?) happy growing