Yellowing copper leaves late flower

yup your bang on pal its cal mag which is causing the brown spots and nitrogen is causing the yellowing if you plan on harvesting in the next week then this is what your after :) you want her to use up all them sugars she has stored in them fans in order to convert them to energy and continue to ripen your buds this is a good sign that the plant is uptaking nutrients as it should be an in my opinion a good flush always leads to much smoother and tasteful flower than non flushed but that is just my opinion alot of other growers will disagree :) Congratulations anyway you have done a fantastic job :) Keep up the great growing !