Just hang in there
I do not see any mag/cal deficiency. I believe the yellowing at this time of budding is normal. The lady knows she has to take all she has in the way of "stored" nutrients. Thus she is using up what she has. I would spend more time looking at her and being amazed. She is a brute. And adding more cal/mag is not going to change the yellowing, AT THIS time of her life.
You may want to put a fan in there to circulate the air as mold loves wet and muggy conditions.
Look at all of that frost !! SWEET.
Love and Light to everyone.